Building the "new" Prowler Aviation, Inc.

A Prowler For Sale + Spoilboards and Skin Flanges

2012-02-10T15:28:00.000-08:00

Hello Everyone,
Thanks for stopping by. The past two weeks yeilded 5-6 more days in the shop. It woud have been more, but I had to do my 2011 taxes, honey-do's, and some kid stuff. Overall, it's been a fairly productive couple of months in the Prowler shop. The time required on the day-job is going to step up for the next several weeks, but then I'll have "Pop in the Shop" the last 10 days of March - so we'll get something done then, for sure. In this update:

1. George Stopped By The Shop.
2. A Prowler For Sale
3. MotionMonster Spoilboard Refacing.
4. Main Spar Center Section.
5. Center Section Skin Flanges.
6. Chuck's Having A Blast.

I didn't work much with the press brake in this past two weeks. I'm still working things out (in my mind) as to how to "calibrate" this machine. I'm now certain that it will bend this aluminum, and it will make nice bends. The trick is going to be getting it to bend at the desired angles, consistently. The other trick is going to be trying to get "calibration data" without cutting up and wasting a bunch of 2024-T3 that cost $250 a sheet. So, it's the next item on the agenda, and I plan to work on this exclusively the next days I get in the shop. Mostly, my progress on the airplane will soon grind to a halt because every part needed to complete the spars will be needing to be bent in the press brake. So, like many things in life, the criticality of needing this process to work will soon take over and "drive the bus" for a while.
The upside to this is that when I finally conquer the beast, I will have production processes in place to produce about 50-60% of the airfame (minus the landing gear and some torque box parts). Approx. 10% would be all the chromoly steel welded parts in various places on the airplane. The remaining 20-30% involves the process of rubber pad pressing (low budget hydroforming) to make all of the formed parts (wing ribs, bulkhead formers, etc.) I've discussed a lot of this technique and the future plans for it in previous posts. With that being said, on with the update.

1. George Stopped By The Shop - George stopped by the shop last week to drop off the flyers in the segment below. He has recently gotten hooked up to high speed internet and has found our blog site. He came by to ask if I would post the for sale flyers he made up for his airplane on the blog. At 84 he is doing great and even thinking about undertaking a Prowler project - for something to do. If anything develops on this front, I'll report on it in a future post.

2. Prowler For Sale - George has had his 3rd Prowler for sale for a while now. These are the flyers he asked me to post here on the blog. The airplane is currently hangared at the Red Bluff, CA airport (KRBL).

If you are interested or have any questions, George's contact info is on page 1.

3. MotionMonster Spoilboard Re-facing - I finally got around to cleaning up the spoilboard on the MotionMonster. This has to be done anytime you mount a new spoilboard on a CNC router. There are two main reasons for needing to do this: 1) the main X and Y axes are not perfectly parallel to the top of the vacuum table that the spoilboard is installed on; 2) The spoil board is not a uniform thickness. In the case of the MotionMaster, the main stationary gantry that is the X axis (and has the spindle carriage mounted to it) is pretty large and heavy. The best that I can tell, the gantry is about 0.030" out of parallel with the vacuum table/spoilboard. That's not bad, considering the thing weighs in at about 2 tons. There are several ways to try to physically make the gantry perfectly parallel to the table. But, for this small amount the easiest way is to just shave off the difference. Here's a picture to show what's involved (angles are exaggerated and amplified for clarity):

As you can see in the pic above, if the surface of the spoilboard is not perpendicular and planar to the spindle/tooling, then in order to make sure that the cutter clears the bottom of the material on one side, you have to cut even deeper on the "high" side. So, the solution is to cut the entire sheet down to be even all over the face of the spoilboard. Then, when you lay a sheet of material down to cut, the cutter will cut below the bottom of the material by the same amout all over the spoilboard. Here's a pic of the facing operation. It looks like a lot of material being removed, but in reality it is less than 1/16th of an inch. I used a 1-1/2" mortise end mill with a 1/2" step-over to cut the face of my spoilboard down. It was a little dusty, but it worked well, overall.

4. Main Spar Center Section - When edge milling the parts of the spar made from the thicker sheets of .100" and .160" (described in the last post), you find out that it doesn't take long before you can get a razor edge on the corners of all the milled pieces. This is particularly bad in two respects: 1) you can get some really nasty cuts; and 2) it is a property of most metals to form stress cracks (from fatigue failure) at the thinnest point in the material. These stress cracks, once started, will propagate thru the material if left unchecked. So, to prevent this from happening, you simply file the edges with a single cut mill file so that the edge has a small radius. Now, you take these fatigue stresses and spread them out over a bigger surface area and the cracks are less likely to start.
Well, doing this to exactly 18 edges on 19 pieces might be simple, but it is also tiedious. So, over the past couple of weeks I would do one or two pieces a day, while the router machine was running and it helped to spread-out the "tediousness" (is that a word?). Anyway, now all of the thick center spar pieces are done and waiting to be hit with the scotchbrite and then the alodine. Here is the "stack."

5. Center Section Skin Flanges - With the spoilboard faced off and armed with a couple of new 1/8" router bits, I decided to give another try at cutting parts. I was a little "gun shy" of going at this again, with the number of broken bits in my router parts box far outnumbering the ones that are still in tact. But, I "manned-up" and turned on the machine. I started using a new style of bit for the first time. This time a used a 2 flute, straight flute, 1/8" carbide cutter. The straight flutes are very good for this profile type cutting application because it puts all the cutting forces directly parallel to the centerline of the material and does not try to lift the material off of the vacuum table/spoilboard (like a helical cutter does). It works much better. This time I also started with a lot higher spindle speed and a lot lower feedrate. I started with 12K rpm on the spindle and feedrate at 4ipm. I could tell that I was making aluminum powder for chips so I slowly, step-by-step kept moving the feedrate up and by the time I was done I was cutting at 14K rpm and 10ipm. I managed to cut out the 10 pieces of the center section spar skin flanges without breaking a bit. So far, so good - I still have the same cutter in one piece! Here's a couple of pics:

These are the lower skin flanges for the center section spar being cut.

It turns out that at 14K rmp, I should actually be able to feed that cutter at up to 18 ipm. So, on my next attempt, I'll step the feedrate up a little more. Overall, I'm very happy with the results. The parts come out with a burr on the edges (as expected), but they are accurate. I can match skin flange rivet holes to the holes in the spar caps - and they match, perfectly! This CNC stuff really works. It's encouraging. I am imagining the possibilities to be able to do "matched hole drilling" for most of the parts of the airplane. The time savings for future kits (builders) would be huge - as compared to previous methods. Rest assured, I will be working this into the prodcution process whenever and where-ever possible.

6. Chuck's Having a Blast - Just one quick builder update this time. I have it from a reliable source that Chuck has been flying his Prowler quite a bit lately. He is apparently "having a blast" flying his plane. Rumor has it that the airplane has been operated fairly close to the speed limit, fairly close to the (minimum) altitude limit, and in VERY close proximity to his own house! Huh - imagine that. Congratulations Chuck.

That's about all the news that worth using up electrons to post about. I expect with the work sked coming up and the folks visiting in late Mar, I'll probably try to post an update in early Mar and then again in early April.

As always, thanks for stopping by to check on the progress here at Prowler Aviation.

A Little More To Report

2012-01-29T09:46:00.000-08:00

The day-job has been really slack the past 3 weeks since the holidays are over. This has provided me with a lot more days in shop. And, these (otherwise) wasted weekends where I sit around in LA waiting for the phone to ring have provided ample time to keep the blog up-to-date. Unfortunately, the crazy days of summer (when everyone is constantly calling in sick) are just around the corner. But, I'll make the best of this while I can.
So, here's what's up lately:
1. Chromate Conversion of Spar Parts.
2. Main Spar Center Section.
3. Press Brake.
4. The CNC Router Vacuum Table.
5. Chicken Run.

1. Chromate Conversion of Spar Parts - In preparation for corrosion treating the wing spar parts, I've located and purchased a 10lbs pail of Iridte 14-2. I found it in the LA area at a place called Gallade Chemical. I paid $26/lbs for the dry power which will make up to 5 gallons of the solution (per pound of dry powder). Aircraft supply places are charging up to $35 per gallon. So, buying dry and mixing my own solution is definitely a substantial cost savings.
The problem is, now I have to get this stuff back to the shop in NorCal. I thought that I'd be able to FedEx it, since they do accept HazMat for shipment. Unfortunately, they only accept HazMat items from DG certified shippers (Dangerous Goods) . So, now I have 2 options: 1. Find a certified DG shipper that will accept this stuff and ship it for me, and ; 2. Drive it home myself between 2 of my reserve stints down here in LA. I need to call and get a few quotes to see what the shipping option will add to the cost of the material .vs. buying gas to drive it home. We'll see.
After my last post on this subject, Cabi suggested simple wooden pans lined with poly film. After checking into it, we decided that this is probably the most cost effective, simple solution. I will, no doubt, be building these boxes in an upcoming blog update.

2. Main Spar Center Section - I've been working diligently to get the center section of the main spar ready to chromate and assemble. Here's the progress. I started by temporarily assembling the spar parts using pins (roofing nails - hey it works!) in enough of the rivet holes to ensure the parts were lined up in the same way that they will be when permanently assembled.

Machining the bearing blocks is the next step, so I had to measure the room available between the bottom of the top set of cap strips and the top of the bottom set of cap strips. Well, this varied depending on which cap strip happened to be sticking out the most (from the rest). This made it obvious that I'd have to machine down all the cap strips (assembled as a single unit - minus the shear web). So, after taking the "stack" back apart, then re-assembling only the bottom strips into a stack and putting it into the mill - here's what it looks like (sorry, the pic is a little over exposed):

The object here is to even out the edges of the cap strips to a uniform dimension so that the bearing blocks can be machined to go between them. This unevenness is a result of the "manual" process used to fabricate these parts before I got up on the CNC production processes. When I make these using the CNC processes, this will not be a problem (for future kits). Here's a shot that shows the before and after of this step:

With this step completed for both the top and bottom sets of cap strips, now a definite measurement could be made of the space between the top and bottom sets of caps strips. Then the machining of the bearing blocks could begin (knowing this new dimension). Here's the raw stock being prepped, cleaned up, squared:

Here's a shot of one (of 4) bearing blocks getting the initial hole bored.

This was pretty close to the limit of use of a hole saw, but it worked and the finish didn't matter since the hole will be cleaned up in the next step.

This rough hole is then opened as needed with a boring bar:

Here is the first test fit of the bearing blocks onto the area of the spar between the caps. Of course, it's close, but doesn't quite fit. A little more machining on the bearing block edges fixed that.

When I got the thin portion of these bearing blocks down to 1/16" I stopped taking material off of the bearing blocks and went back to removing material from the appropriate sides of the cap strips (more milling). Eventually, I got the bearing blocks to all fit nicely on both sides of the spar web. Here's a shot:

And some close ups:

Notice the bearing blocks are sticking out farther that the cap strips. These need to be flush to the cap strips (plus 0.040" for the skin flanges that I'd forgotten about up til now - yay). So, now I just need to face mill the bearing block to the correct thickness, like this:

Here's the completed bearing blocks (minus face milling) with the bearings installed. Here you can see that the forces of the main landing gear torque tubes are transferred to the bearing blocks, which in turn transfer these loads to the spar cap strips and web, and eventually into the entire wing (which is what you want to have happen):

The one remaining step is to drill and tap a hole in the forward bearing blocks to insert a grease fitting for periodic maintenance (some day).
Once the bearing blocks were installed, I had to re-assemble the "stack" and clean up the edges of the cap strips on the top and bottom of the spar. Here's the whole stack set up for doing this. I decided to do this by hand rather than try to get this whole (100 lbs) stack into the mill:

The file you see sitting on the top of the spar stack is a babbit file. George told me about these files and they do a great job of cleaning up the edges of thick AL pieces. They are actually made for filing large journal bearings made of babbit, but work great for this too. Here you can see a before and after of what the edges of the spar stack looked like. In the before pic you can see the router marks on several of the edges. On the after shot you can see the router marks removed and a nice smooth edge in it's place:

With all of this done, here is the spar stack completed with the bearings and bearing blocks installed:

Now, I still have to cut out the skin flanges for the main spar center section. This actually consists of 10 pieces (3 on each top edge and 2 on each bottom edge). I will have an update on fabricating these in a future post. I also have to clean up the faces of each of the spar parts with a scotchbrite rol-lok disc. These work great to clean the junk off of the aluminum. I started to do this (you can see the top cap strip above is more shiny than the bottom one and the shear web). But, I didn't continue to do this to all the parts now, since the metal would start to oxidize again before I get to the chromating. I decided that it would be wiser to do this just before the chromate conversion process, since this will make the etching step go more quickly.

3. Press Brake - In the last post, I showed how I installed the hydraulics to make the press brake operational. Well, with the hydraulics worked out it was time to start trying to "calibrate" this machine and figure out a process to get consistent bends out of it. I started by fabricating a "stop" system to stop the lower die beam at a pre-determined point. What I came up with was a 1/2" thick piece of flat steel that was 4" long and 2" wide for a top stop. This piece was bolted to the side frames and is mounted up to the upper die beam. On the bottom I used a 1" thick piece of steel to use sit on the lower die beam. Using these pieces in this configuration will provide for the use of calibrated "stop blocks" that do not have to be large and/or tall. Here's a pic:

The area between these stop pieces is where the calibrated "stop block" will be placed. Then, when the hydraulics is activated, the lower die beam will move up until it hits the stops. There will have to be a different stop block made for each angle of bend that is desired. Also, the LH stop blocks are not the exact same thickness that are required on the RH side. So, I'll end up having a set of 90 degree stop blocks, a set of 85degree stop blocks, etc.
In order to try to determine what the "ballpark" value will be for each angle of bend, I next cut up several 1-1/2" x 2" pieces of 2024-T3 (0.040"). I used these pieces to do test bends to collect empirical data to use to plot on a graph. Using different thicknesses of stop blocks I bent test pieces for each and then measured the resulting angle of bend. Here's the pieces that I used to obtain this data:

Then, I plotted this data to get this:

As you can see, this is a pretty linear relationship between bend angle in degrees along the X axis and the associated stop block thickness along the Y axis. The red data and line is for the RH stop block and the blue is for the LH stop block. The difference in thickness (for the RH and LH blocks) is the result of the stopping system on the LH and RH not having the exact same gap between the upper stop and lower stops. So, overall this data made sense and seemed to give some positive results. But, when I tried to machine a stop block of a given thickness and then get the bend angle that is indicated in the graph, the results were not consistent. I could use the same set of stop blocks and bend three pieces and get three different bend angles. There seems to be too much variability in the process to give predictable results.
After pondering this for a long while, I've come to the conclusion that the biggest variable factor is the pressure being developed in the hydraulics. I do not yet have a pressure gauge installed. Without a gauge, I am likely stopping the bending process on any given piece at a different pressure than the next. This difference in pressure is probably responsible for adding much of the variability to the data (bends). Another factor in play here is that the difference in pressures is most likely causing more or less flexing of the dies (more pressure means more die flex) and this is giving the different bend angles for a given set of stop blocks.
I have an idea for a bending process that may take a lot of the unpredictability out of the process and give consistent results. I just need to come up with a process that gives predictable results before I start tying to bend $100 parts and have them come out messed up and unusable. I'm going to be trying this (more testing) in the upcoming week and I'll have an update in a the next blog post.

4. The CNC Router Vacuum Table - Before I can cut the 10 needed skin flanges for the center section of the main spar, I need to face cut the vacuum table spoil board. I've measured it, and there is about 0.035" difference between the "high" corner and the "low" corner on the spoil board. Now that I've got an acceptable cutter to machine off the "unevenness" of the vacuum table, I have to write a G-code program to get this job done. Here is a pic that shows a section view of how my spoil board is mounted to the vacuum table:

The process of face cutting the top of the spoil board is needed because if the top of the spoil board is not perfectly perpendicular and planar to the spindle, it is more difficult to cut an even distance through a sheet of aluminum laying on top of the spoil board. When you are trying to profile cut parts, you want the end of the cutter to stick out about 0.010" below the bottom of the sheet that you are cutting out of. This eventually "spoils" the board (hence the name) and you have to re-face the spoilboard. So, you can consume most of a sheet of MDF in this process before you need to completely replace it. I am going to try to accomplish this first face cut in the upcoming week as well. I'll have an update in the next post.

5. Chicken Run - The kids have inherited a few more chickens recently, and suddenly the chicken coop is not large enough. With 3 girls batting eyelashes and asking for help, what's a dad to do? A new, larger chicken run to attach to the existing coop. So, here is where a few man-hours went recently.

Lucky chickens!

Well, that's all that's happened in the shop over the past two weeks. I should be getting 2-3 more good slack weeks from the day-job - maybe even a month yet. I'll be in the shop trying to get this wing spar ready to mount in the jig. That's the main goal for now and I'll be keeping the focus on this for the time being. Thanks for stopping by to check on the progress. I'll plan on another update in two weeks.

Happy New Year!

2012-01-14T22:40:00.000-08:00

Happy New Year everyone! One of my new year's resolutions this year is to try to do more Prowler posts, more often. I've gotten a few things accomplished over the holidays, so an update seems in order.

Since the last update I have finally gotten some parts cut out with the CNC router using the same process that I will use in production some day. I coaxed the MotionMonster to cut out a set of outboard wing spar shear web channels and a do-over of one of the outboard spar cap strips. So, now I have all of the 2024-T3 aluminum parts cut out for the entire wing spar (from wing-tip to wing-tip). After that I have completed the build work on the 8 foot press brake and did one quick test bend.

Here are the topics for this update:
1. Production Parts with the MotionMonster.
1.A. Outboard Wing Spar Channels.
1.B. Outboard Wing Spar Cap Strip.
1.C. Need To Face Cut The Vacuum Table.
1.D. Recap of The Entire Process.
2. Finished Building the 8 Foot Press Brake.
2.A. Building The Back Gauge.
2.B. Building The Beam Deflection Meter.
2.C. Converting a 20 Ton Bottle Jack Into a Basic 20 Ton Ram.
2.D. Assembling The Hydraulics.
3. Researching How To Alodine Aluminum.
3.A. The Chromate Conversion Process.
3.B. Finding The Chemicals.
3.C. Need A Pan
4. Next Update

First up is the new parts made with the Prowler MotionMaster (PMM).
1. Production Parts with the MotionMonster - I'm really focusing on trying to get the wing spar mounted into the wing jig by this March. Before I can do that, I have to have the spar assembled. Of course, in order to do that I have to have all the parts collected. In the last update I posted about making the fixtures and finishing the spar cap strips, etc. Well, after that I got the time to make the remaining parts that I was missing. Namely, the outboard wing spar channels and one cap strip that needed to be replaced.
1.A. Outboard Wing Spar Channels - Here is a pic of the machine cutting one of the two spar channels that I need to make. The machine worked great.

Here's a video of the same part being profile cut:

1.B. Outboard Wing Spar Cap Strip - I had to replace one of the cap strips that is the closest to the spar web on the forward side of the spar. The one that I had cut previously came off the edge of a new sheet. Not knowing at the time, I just used the edge of the sheet as one edge of the cap strip. Well, that doesn't work well. Turns out that there are internal stresses that are built up in the material on the very edge of factory sheet. If you cut a thin strip off that edge, it will come out all warped and twisted because the factory edge has stresses and the newly cut edge releases those stresses. Anyway, I didn't like that piece, so I cut a new one. Here's a pic of the profile cut on the outboard end:

And, a profile cut of the inboard end:

1.C. Need To Face Cut The Vacuum Table - one problem that I encountered while making these parts was the fact that the vacuum table spoil board was not perfectly parallel and planar to the gantry of the router. So, one side (and corner) of the table was lower than the other. Well, if you are trying to maintain a constant depth of cut in a part, it doesn't work real well to have an uneven spoil board. The solution is to face cut the spoil board with the router over it's entire surface. Then there will be an exact equal distance from the router to the table everywhere on the spoil board. To do this I needed a cutter that would accomplish this. Looking on the forums at CNCzone and Practical Machinist - I found that guys use a variety of tooling to do this, but a simple 1-1/2" end mill with 2 flutes will work fine.
It just so happened that when I picked up the machine I also got a free slab of nylon with a collection of several end mills stuck into. They looked pretty ratty but I decided to clean them up to see what I'd gotten. Turns out that there was a pretty decent 1-3/8" mortise mill in the bunch - but just needed sharpening. I found a local gent that does AWESOME tool and cutter grinding. He fixed up about 6 of these end mills for me and now I can face off the table. I'll cover that in a future post.

1.D. Recap of The Entire Process - For those not familiar with CNC production process, I thought I'd recap the entire process to give some perspective. There are a lot of parts to the puzzle and this will help give an insight as to the work that's been involved to get to this point in the Prowler production process. So, this is the way that I've done things. If anyone has any ideas to streamline any of this - please share.
1. First I had to create the CAD drawings. I've made many posts about this. In the CNC world, this is where it all begins. To make my CAD drawings I bought and learned how to use a CAD software. Then, I reverse engineered all of the Prowler parts, using a variety of techniques, that resulted in a CAD drawing. For the spar cap strip mentioned above, the CAD drawing looked like this:

2. Next, this CAD drawing has to be stripped down to only lines, points a circles. This is so that it can be correctly converted into a .dxf (a sort-of CAD drawing standard). When I'm done with that, it looks more like this:

3. Then, I take this drawing file and I feed it into a software called SheetCAM. The CAM process takes the drawing and converts into tool paths (paths for a tool to follow). In SheetCAM the same part looks like this with all of the holes and profile cuts programmed.

Here's a more close up of one end to show a little more detail. The S's depict start points for SheetCAM. In this case, each point on the DXF drawing becomes a start point for one drill operation. That's why there are so many S points on this SheetCAM part.

4. When everything is set-up correctly, you tell the CAM software to do something referred to as "Posting." Posting is where the toolpaths are created for your specific machine using something known as a "Post Processor." When the post is done, the CAM software has basically created a text file with a bunch of numerically ordered commands. These commands are called G-code. G-code is a very low-level, simple code that tells the machine how to move in X,Y and Z coordinates, when to turn on & off parts of the machine like the spindle, coolant, etc. This is what it looks like:

5. Now I go to the laptop that I have essentially hardwired to the CNC router controller. I have to transfer this G-code file to that laptop. Then, I use a software created by Fagor (the company that makes the machine's controller) that is called WinDNC. Using WinDNC I can transfer the G-code program into the controller's memory. If the program is too large, WinDNC has an "infinite" transfer routine that will allow the program to be fed to the controller on the fly, while it's cutting parts. In the industry this is referred to as "drip feeding" the controller. This will definitely get used, since this 14 year old controller has a WHOPPING 32Kb of memory! Yes, that's kilobytes with a K! So far, the biggest file I have cut was the center wing spar web (holes and profile cut) that had a G-code file that was about 13Kb. Here's a pic of the laptop and the controller:

6. With the part program in the controller's memory, I can call the program up and get ready to execute the program. But first, you have to run a warm-up cycle on the machine (before the first run of the day), then you have to load the material onto the vacuum table. Next, I test run the part program with the router set to a "slow" mode that executes one step at at time and with a work offset that keeps the router 1" above the material all the time. During the test run, the sheet of material can be positioned properly, and all the steps can be confirmed to make sure that something funky isn't going to happen. This helps prevent ruined parts, broken end mills, etc.

7. If everything looks right, you can hit the "cycle-start" button (big green button in the lower right corner of the controller above) and start to cut the part. If all goes well, it should look like this when its running:

8. Now, this has to be done for each part (or group of parts) of the plane. However, once I get closer to production, I will be able to group parts that use the same thickness of sheet aluminum together and cut them out in one big program. The ideal idea here would be to have all the, say, 0.040" parts of the airplane gathered together on 4 or 5 sheets of material - for example. Then, to cut out one plane's worth of 0.040" parts, you'd have to run 4 or 5 programs that would make the majority of those parts. At least, that is the ideal scenario - the reality may turn out to be something different. Time will tell.

Well, that's my experience of CNC production so far. As the learning curve flattens out, things will go more quickly. I hope this helps give you a better idea of what is going on here. The real value of this process is that parts on future Prowlers will be interchangeable. Anyone that has seen more than one of these current airplanes will tell you that this is not possible with the previous Prowler kits.

In the previous post I showed how I cut a ba-zillion rivet holes in about 50 spar parts. When stacking them all up on the bench together, THEY ALL MATCH!!! See this:

I can now do the so-called "matched drilling" of Prowler parts that is accurate to one-half of one thousandth of an inch ( That's = 0.0005"). To use a Bryan Davies quote - "THAT'S WAY COOL!"

2. Finished Building the 8 Foot Press Brake.
2.A. Building The Back Gauge - In order to have a semi-accurate method to control the width of the flanges that are bent with the press brake, I needed a back-gauge to allow the material to bump up against before pressing. I started by making some J-hook devices to grab the side of the U channels that support the back-gauge.

Then I welded nuts onto the J-hooks and made up bolts that go thru the back-gauge into the nuts on the J-hooks. I machined slotted holes into each of the back-gauge for these bolts to go through. This works well to set the end of the back-gauge and then tighten it down with the bolt to hold it in position.

I took the U channels and slotted the tops to a depth of 0.025" to allow the metal scale to be set down into the slot.

Here you see the scale, the slotted holes and the hold down bolt. This will be used to set the distance for the back-gauge to the size of the flange desired and then clamp the back-gauge in position.

Here's what the whole system looks like installed on the back of the press brake.

Next up was installing the "deflecto-meter".

2.B. Building The Beam Deflection Meter - In order to accurately control the plunge depth when bending metal, it's best to have a ram located at each end of the beam that has the lower die attached to it. In this configuration, however, the beam will deflect (down) in the middle (due to the resistance of the piece that you're bending) when the rams are lifting on each end.
Here is a bracket that I welded onto the center of the sliding beam and then attached a dial indicator. Below the dial indicator you can see the edge of a 3/16" by 4" flat bar that is mounted to the face of the sliding beam. This flat bar is only mounted to the sliding beam at the ends of the beam. This way, when the beam deflects up on the ends (and down in the center) - this flat bar moves up with the ends of the beam. This movement will be displayed on the dial indicator (see 2 pics below).

Here you can see the press brake with the bar installed on edge onto the face of the sliding beam and bolted at each end. You can also see the dial indicator mounted in the center.

Here is the dial indicator mounted with the "shelf" in position pushing up on the indicator probe when the beam deflects.

This will be used with (eventually) a third jack. This center jack will be used to jack out the deflection when pressing a flange into a piece of metal. Jacking the outer jacks will do most of the work bending of the flange and cause the beam deflection, then the center jack will just take out this deflection to ensure a straight and accurate bend. During test bends, I was seeing deflections of 15-25 thousandths. In terms of angle of bend, that's about 2-4 degrees of bend. I've calculated that on a 90 degree flange bend, each 0.006" (approx) of plunge depth corresponds to about one degree of bend angle.

2.C. Converting a 20 Ton Bottle Jack Into a Basic 20 Ton Ram - This is a little off topic, but I thought that I would include this section in case anyone ever wants to convert a cheapo bottle jack into a hydraulic ram. Someone googling "convert bottle jack to hydraulic ram" might find this info helpful. The idea here is that a bottle jack has a lever operated pump that pumps hydraulic oil (up to 10,000 psi) under a piston to produce (forceful) linear motion. By machining an auxiliary port into the area under the piston you can use a separate source of hydraulic power to lift the piston (and ram). So, here's how I did it.
1. Pull the reservoir plug and drain the hydraulic oil out of the jack.

2. Now, remove the bleeder valve and drain any residual oil from it. You might have to tip the jack around a bit to let the air into the bleeder valve cavity so the oil can drain out. If you don't do this now, it's OK - but the oil will eventually come out. It'll just come out where you might not want it to - when you least expect it to.

3. Hold the base of the bottle jack in something that is rigid and strong. I used a large vise, but I had to make sure not to "pinch" parts of the jack that you don't want pinched. The inside jaws of the vise have ahold of one end of the flat part of the base of the jack.

4. Remove the big retaining collar at the top of the jack. This is really nothing more than a big hex nut that squeezes down on the reservoir outer jacket and seals it between a large flat rubber washer on the bottom and the top to form the outside of the reservoir. These parts will be on tight and will require large tools, lots of uumphf, and sometimes a 3 foot cheater bar to get them to loosen up.

5. Now remove the reservoir outer jacket. You can see the flat rubber seal on the top in the pic above and in the pic below you can see the rubber ring that seals the reservoir on the bottom.

6. Next, you'll need a big pipe wrench to remove the hydraulic cylinder. This is just a piece of high strength steel pipe with threads on each end. It's the cylinder that the actual piston and ram travel in when moving up and down.

7. Once you have the base of the cylinder loosened you can remove the piston and ram. I waited until I had the base loose before removing the ram so that I didn't get any junk inside the cylinder. But, with the bleeder valve removed, you can pull the ram out at any time.

Notice that the piston is just a little bigger than the ram on the bottom. That's the part that hits the big nut on the top to prevent it from flying out of the cylinder when it reaches the top of the cylinder. It also "counts" in the surface area when calculating the force of the jack.

WARNING! - MATH SIDE-BAR - FOLLOW AT YOUR OWN RISK!
The force of the jack is equal to the fluid pressure times the surface area of the piston (F=P*A).
Area of a circle is pi times radius squared or A=pi*(R*R).
Also, radius R is 1/2 the diameter (R=D/2).
Bottle jacks (I've come to find out) are designed to develop 10,000 psi.
After all the substitutions, then the force of the jack can
be expressed as F=P*pi*(1/4)*D*D.
Now, solving this equation for D
gives us the following: D=square root [(F*4)/(P*pi)].
In the case of this 20 ton bottle jack
D=square root [(40,000lbs*4)/(10,000psi*3.1416)].
A quick calculator operation gives D as 2.25 inches.
My ram is 2" and the piston adds the .25 inches.
Hey, math works! At least that's what I'm trying to convince my kids of these days.
Back to the conversion.

8. Remove the cylinder, the rubber seal rings and clean up all the oil. Remove the lever pump inlet screen (first pic below). Then remove the little plastic corner mold piece in the bottom (second pic below). I'm not sure what this even is!?!?! But, I didn't want to get machining chips stuck under it, so I took it out for next few steps.

9. Mount the base of the jack in a mill, mill-drill, or even an adequate drill press. Here's mine:

10. Find a suitable place to machine in a hole for the aux port. Used a 1/4" NPT male to 3/8" NPT female adapter to connect hoses to my rams. I chose this because when you go looking for 10,00 psi hose, they all come with 3/8" male fittings on the ends. So, the next size down seemed appropriate for the aux port. For a 1/4" NPT femal hole you'll use a 9/16" hole with a 1/4"-18tpi pipe tap. I used a 9/16" end mill, but a regular twist drill bit would work. I'm sure that different jack manufacturers will have different base configurations. In my case, I used HFT 20 ton bottle jacks and they have this nifty little flat spot cast into the side of the base opposite the lever pump. Imagine that! I wonder if that might have been for, say, an auxiliary port!! No - you don't say!

11. Make the hole. Try to position the holes you make to keep as much material surrounding the holes as is possible. This will help the base maintain it's strength with 10,000 psi trying to rip it apart when you are using it. On the 10,000 psi hydraulic fittings I used I measured a wall thickness of around 3/16". So, for steel, I tried to maintain that wall thickness everywhere I could in the base of the jack. I machined my big 9/16" hole to a depth of 3/4". This should be enough to get the tap all the way in as far as needed.

12. I then drilled a 1/4" port from the bottom of this hole deeper into the jack base until it is under the piston area. The hole is offset from the big hole since I was trying to shoot for the middle of the material in the base of the jack.

13. Then I tapped the big hole while the base was conveniently held on the mill. I learned a neat trick from a friend for starting taps straight. Use a large flat surface (like an upside down 3/4 end mill) in the spindle to push down on the top of the tap. Then keep pressure down onto the tap with the spindle handle while you turn the tap. A little oil on the top of the tap helps. This will keep the tap straight up and down while you get the first several threads cut. Then you can lift the spindle out of the way and continue to tap the hole. Worked good.

14. Continue to test the fitting into the new threads. Ideally, you are looking for 2/3 of the threads on the fitting to screw into the hole. If you're not getting that, take the fitting back out and cut a few more turns with the tap. I found out that cutting pipe tap threads is very different than cutting bolt hole threads! Especially if you don't taper the hole - which I did not. My tap (with several missing thread lands now) shows the error of my ways. But the tap was only $5 and it got the job done.

15. Now I turned the base flat and machined in a short hole down from the top of the area under the piston to meet the 1/4" hole that I previously drilled. This will complete the port into the area under the piston. Make sure it lines up!

16. Ta-Da! An auxiliary port is now installed in the 20 ton bottle jack. Well, not quite. We still have to put it back together. Here you can see the new port (it's the one at the bottom of the picture). The port that is on the top (inside of the threaded shoulder that the cylinder threads into) is where the hydraulic oil comes out of the lever operated pump. The little plastic do-hicky holds the check valve ball in place and keeps it from unseating if you tip the jack upside- down. As you stop each stroke while hand pumping the jack, the pressure inside of the cylinder pushes down and seats the ball tightly - preventing the loss of pressure inside the cylinder until the next pump stroke. When using an auxiliary port (and pump) this ball valve just stays seated and no pressure gets back to the lever pump. The lever pump gets is oil from the reservoir which is the hole at the very top of the pic. The reservoir is the area between the threaded collar and the outside jacket of the bottle jack.

The hole on the right (inside of the threaded collar) is where the hydraulic fluid leaves the area under the piston when you crack the bleeder valve to lower the jack. This oil then comes up into the reservoir thru the hole at the very right (again between the threaded collar and the outside jacket). Oh, you can't see it in my pictures, but I put plugs in all these holes before I started cutting any metal to prevent chips from getting where the don't belong.

17. Now do steps 1 thru 8 in reverse to put the jack back together. Don't forget to very carefully clean ALL of the little chips and metal shavings out of the entire jack. You can re-use the hydraulic oil, but I filtered mine thru a paper towel first to get rid of any metal shavings, paint chips, etc. When screwing the cylinder back it, put all your might into it. If it's as tight as you can possibly get it, then it's probably tight enough. The big nut needs to be tight, but not hugely tight. It doesn't seal anything, all it does it hold the outer jacket in place (between the rubber seals) and acts as a stop for the piston travel. So, make it good and tight, but don't cut thru the rubber seals.

I did this with two jacks for the press brake project. Here's what they looked like when I got finished:

The real beauty of doing this with a bottle jack is this. If you find that you don't want to use it as just a ram with an aux pump any longer, you just put a 1/4" pipe plug into the hole - instead of the 1/4" fitting you see here. The jack is then back to being just a bottle jack and operating just as it did before the conversion. Sweet!

2.D. Assembling The Hydraulics - With the bottle jacks converted to rams, it was time to start putting it all together. Next there was a trip to the hydraulics store to buy the hoses, fittings, and more fluid. Then a trip to HFT to get this air-over-hydraulics pump.

I chose this pump since it is fairly inexpensive and I wanted to try to keep the cost down until I knew for sure that this thing was going to work. As it turns out, it works pretty well. So, the first step was to put the fittings into the jacks, then connect the hoses to those fittings. Next I had to machine a junction block to split the hydraulic fluid flow from the one pump into two lines (one for each jack). Here are a few pics

With the junction block made up, I attached the pump hoses to it and then connected the pump with a hose to the junction block. Once I got to this point I had to fill the lines and jacks with fluid and get the air out. I set it up next to a ladder to string the parts up and keep the air moving up as I put the hydraulic fluid in. After this pic was taken, I taped a broom stick to the leg of the ladder and taped the end of the hydraulic line up to it. Then started filling it with oil. After I got the lines filled with oil I turned the jacks over and around to work the air bubble out of the jacks. I did the same with the junction block. This worked well.

Once this was done I connected the line to the air-over-hydraulic pump and then bled the air out of the pump. Then I installed it into the press brake and it now looks like this:

The junction block is on the back side of the lower beams. Pressing the foot pedal moves the lower beam up plunging the upper die down into the lower die. The metal gets bent in a process called "air gap bending" and is depicted by this drawing:

I did one test bend with a 7 foot ratty old piece of sheet steel that I had laying around the shop. The press brake worked really well - the hydraulics worked great, the deflection measuring system worked very well, the back-gauge works great, and most importantly the bend came out nice and straight. I have more tweaks to do to the system, but overall this purpose built machine is working out well and I'm pretty happy with the results.

Now that the hydraulics are working, I'll start to begin the process of calibrating the press brake to determine the exact plunge depth that will give the best bend results for each desired angle of bend. Oh, yeah - and somewhere in there I need to work out time for a paint job on the press brake.

3. Researching How To Alodine Aluminum - In an effort to try to plan ahead, I've been researching the Alodine process. Alodine is essentially a form of chromic acid. The purpose of this process is to aid in preventing corrosion in the aluminum. It is believed that this process will protect the aluminum up to 30% longer than skipping the process and painting bare aluminum. It is used in lieu of an anodizing process, because trying anodize a complete airplane is simply cost prohibitive.  Alodine 1201 is actually a brand name of this solution that is made by Henkel (a mega-conglomerate company). There is an alternative to Alodine that is called Iridite 14-2 and it is make by a company named MacDermid Chemical. Dupont also makes this and it is called  Dupont 226s.

After reading many google hits about Alodine and Iridite, I've found out that the real deal with doing this is NOT paying Aircraft Spruce $35 per gallon for this solution. If you like, you can check some of them out here, here, here and here. If you can find the dry powder form, you can get a lot more bang for your buck by mixing it yourself (thus saving about $20 for each gallon of water).

Additionally, each manufacturer has a pre-treatment solution that they recommend. Henkel calls their prep solution Alumiprep. MacDermid calls their solution Isoprep 188. Dupont's prep is Dupont 225s. Turns out, this solution is an etching solution that cleans the aluminum very well before treating with the chromic acid. This solution is really just a 1/3 mix of water, 1/3 phosphoric acid (75%) and 1/3 ethylene glycol. The phosphoric acid strips any oxidation off of the aluminum, the glycol acts as a surfactant and the water is the mixing solvent. These chemicals are readily available at any chemical supply place.  So, I'll probably mix my own.

3.A. The Chromate Conversion Process - This is actually, the technical name for this process. Essentially you take your aluminum parts, one at at time and soak them for a while in an acid etching bath. Once it is adequately etched, you remove it, rinse it with water and then put it directly into the chromic acid bath. You let it soak in there for a period of time and then remove it and, again, rinse it with water - then let it dry. The exact process is provided by the manufacturer when you purchase the materials. There are also plenty of hits to review if you google Alodine, Iridite, or Dupont 226s.

3.B. Finding The Chemicals - I am having a hard time finding a dry powder form of any of these chromic acid compounds. The only one that I have located is the Iridite 14-2 that I can buy down in the LA area, but I'll have to get it to the shop. Since it is a HazMat item, it's not easy to ship. But, FedEx will probably be able to ship it. I'll have to check. The rest of the materials I'll be able to get locally. I have a chemical company in Sacramento trying to round up all these chems for me. If they can find the powered chromic acid, I'll get everything from them in one order.

3.C. Need A Pan - Trying once again to plan ahead, I think I'm going to have to locate some kind of pan (2 pans actually) to dip these spar parts into during the Alodine process.  One pan would be used for the etch solution and the other one used for the chromic acid. Assuming the center wing spar web is the largest of the spar parts, the pan will need to be about 8'6" long, 18" wide and about 2 inches deep. I remember reading somewhere that PVC works well for these. Now to find something to fit that order. I'll keep you posted.

3. Next Update - As I mentioned earlier, calibrating the press brake is next up on the list along with getting the chromate conversion process completed on the spar parts. I will also attempt to face cut the vacuum table spoil board on the CNC router if the opportunity presents itself. Those will be the focus for the next update, hopefully in a month or so.

As always, thanks for stopping by to check up on us.

Happy Holidays - We're Makin' Some Chips Here

2011-12-24T20:17:00.000-08:00

Happy holidays everyone. Thanks for checking in on us again. It is, once again, time for the year end wrap-up. The big news for this post is the MotionMonster is working. We're making Prowler parts using the same processes that we will (hopefully) eventually use in production. Here's the list of items I have to cover in this update:
1. The MotionMonster is Makin' Parts
2. Short Term Plan
3. The (Pseudo) Hydroforming Process
4. Long Term Plans
5. FWF Update
6. Builder Updates:
   a. Chuck Has Gotten His Experimental Certificate
   b. Bud's Engine Parts Are Fixed
   c. Ray's Engine Work Continues
   d. Roy's Airplane is For Sale
   e. Bryan's Cranking On His Fuselage
7. XP TalonInfo

1. The MotionMonster is Makin' Parts -I've been able to get some time in the shop that past couple of weeks finishing up the installation of the machine and cutting parts. Yep! After 7 months of researching the various components of the machine, figuring out an electric power scheme for it, doing hook-ups, tracing wires, fixing parts, cleaning pieces, getting tooling, figuring out the spindle systems, plumbing chip vacuums, etc. etc. - I finally made some outboard wing spar cap strips with it. These parts had been cut out of a full sheet last March before I knew that I'd be getting this machine. Here's what they looked like then:

I used the CAD drawings that I had made for these parts to run through my CAM software and make the G-code for the machine. But since these parts had already been cut into strips (instead of cutting these out of a full sheet), I had to make a fixture and cut them individually while mounted in the fixture. Here's the fixture I fabricated (with the old pattern laying on top):

Here's a video of the machine cutting the 1/8" rivet holes:

And another video of the machine doing the profile cuts to shape the pieces:

I was hoping to have some pics and/or video to post of the machine cutting production pieces out of a full sheet of aluminum. Unfortunately, the learning curve on the machine is still pretty steep - as evidenced by this:

Since I broke all the endmill/cutters that I had in the shop (and the new ones I ordered hadn't arrive before I had to leave to go to work), I couldn't get the outboard wing spar channel pieces cut out. I'll have to get those done when I get home again next week.
Before I left, however, I was able to get another fixture made to put the holes into the center wing spar parts. Here's a couple of pics:

The pic above is the fixture installed on the table. Below is the main center section spar web that I made years ago installed in the fixture. I used the machine to router out a pocket so that the pieces will just fit into the fixture. This will ensure proper rivet hole alignment of all the spar parts (shear web, top cap strips and bottom cap strips).

As I mentioned, I have had these main spar center section parts cut out and laying on one of the benches in the shop for several years. It was while I was making those pieces that I decided that there had to be a better way to more accurately and quickly produce these parts. This got me started down the path of researching and learning about CNC production techniques. The buying, fixing, and installing the various machines that I now have machines then followed. The plan is (slowly) starting to come together. Speaking of plans, that's the next couple of topics.

2. Short Term Plan -
On the near term horizon I have three goals:
A. The first goal is to go back and create the G-code part files for all of the parts of the airplane that I have already made using manual techniques. When I finish the first "new" Prowler plane, I want to have ALL of the parts made using the CNC production processes. Going back and creating the part files for all the parts that I've already made will get the production processes "caught-up" to the parts that I have already made for the first airplane. I've actually gotten most of this done already for the outboard wing spar parts that I drilled and profiled the past several weeks (mentioned above). I'll get the center wing spar parts done in the next week or so.
B. The second goal is to get the 8 foot press brake that Pop and I built last year dialed in and cleaned up. I need to have it working in order to bend the outboard wing spar channels to meet the next goal.
C. The third goal is to get all of the wing spar parts (center and outboard) cleaned up, treated with Alodine, and assembled before the end of March. That's when Pop will be out for the annual visit and he can help me get the spar installed into the wing jig and leveled up. If you go "way back" in the blog posts, you'll see that we built the first phase of the wing jig almost 4 years ago (Mar 2007)! The pieces of the puzzle are SLOWLY starting to come together.

Once the spar is in the wing jig, then the focus will shift to setting up the production processes and making the parts that will eventually attach to the spar. The most significant of these will be: wing ribs (nose and mid); parts associated with the landing gear; and the fuselage floor pieces. The production process I'm hoping to use for the wing ribs is going to lead to the next big phase of production set-up for the "new" Prowler Aviation. I'll outline this in the Long Term Plan below. But first, more on the wing rib forming process.

3. The (Pseudo) Hydroforming Process -
The process that I'm hoping to use for making wing ribs, bulkhead formers and similar parts is best described by Brian Carpenter in a video that he made for the EAA Hints for Homebuilders. Check this out:

The process that I would like to use is going to be virtually identical to what Brian demonstrated in the video, just on a bigger scale. The main problem with "bigger" is that the forces involved become huge very quickly. The press size becomes enormous as the area increases.
Here's how the math works out. It takes a pressure of about 800-1000 PSI to form the metal that you saw in the video above. Let's be conservative and use the 1000 PSI as our target pressure to ensure our parts get bent completely and properly. Now, the largest part that I need to be able to bend using this process is the fuselage former right behind the cockpit. This part is approx. 34" by 22" which will require a "box" that is at least 36"x24" and gives an area of 864 sq. in. Now, if you want to get 1000 pounds of force in every sq inch, that will require a total force of 864 x 1000 = 864K pounds of force. That means you will need a press that is capable of 432 tons! That is a massive press. If you have a minute do a google search for 600 ton hydraulic presses. You'll see that they are massive and expensive. But, I have a plan.
Once the spar is complete and installed in the wing jig the next step will be to begin to "decorate" it with wing ribs and parts mentioned earlier. Creating the production process for making the wing ribs will be a challenge, but it is do-able. In order to be able to practically and feasibly make parts using this "rubber hydroforming" process, the size of the "box" has to be reduced to the smallest size possible. After reviewing all the alternatives, I have decided (with the help of some of my "advisers") to produce the fuselage formers in two parts. The largest 3 of the 8 fuselage formers will have to be made in two halves and those will have to be riveted together by the builders before installation. Not an ideal solution, but it is an acceptable compromise.

So, by doing this, the size of the "box" is reduced to about 36" x 12" and will require about 200 tons of force. Now we are down to talking about two 100 ton presses possibly configured side by side. Or, we may be able to use four 50 ton bottle jacks in a distributed, purpose built press setup. One way or another, doing this makes the production process a lot more practical and a lot less costly. It's doable. Here's a snippet of an idea that I have:

4. Long Term Plans - Looking a ways down the road, the setup for the production of pressed parts will be become the big project into next year. Getting, buying, or building a press with the capability to make these parts (and not break the piggy bank here) will be the next big challenge for me. I'm fairly certain that I can come up with a home-brew, purpose built press like the snippet shown above. But before I spend the time, effort and money to tackle that, I want to try some of this process on a smaller scale.

To do that, I plan to remodel a hydraulic press that we got from George with the sale of Prowler Aviation. Here's a pic of it as it currently exists:

In a "way back" post I talked about getting that press set up for pressing wing ribs using a male and female die process on soft 2024-O aluminum. That was before I discovered this rubber hydroforming process and after I went through the heat treating process that I also discussed in a previous post. To be able to make these parts in a two step process (#1 cut from a full sheet of 2024-T3 and #2 press into shape in one operation) will greatly simplify my production.

Anyway, I'm going to first test this process out with this smaller press. I plan to remove the wood platens and replace them with the largest steel "box" that I can use in this press, given the 100 ton ram that is in it and the physical size of the press between the left and right columns. I hope to be able to make a box just big enough to be able to form almost all of the wing ribs for the airplane. Then, taking what I learn from this endeavor, I will set out to design and build a purpose built press big enough for all of the Prowler parts I will need to "squish."

Before I can squish out any of these parts, I will need to make new dies similar to what you saw in the video with Brian. Since I plan to (hopefully) re-use these dies many times (meaning lots of kits), I will need to make new dies for any part that has to be squished to become a real Prowler part. That's where this guy comes into play:

Remember the summer before last, when the opportunity to get this machine for a really good price came along? Well, it's time will come (soon), and the overall plan is slowly coming together. I'll be using this to make those dies out of thick aluminum, or maybe mild steel. Also, while I was doing all the CAD work and making the drawings of all of the parts of the plane, I knew that this would have to be done - so I also made the necessary drawings for the dies (to perfectly match the parts) at the same time. Now, I will have those readily available when I need to start cutting dies. The pieces of the puzzle ......

It also turns out that the controller that I'm learning to use to run the MotionMonster is a Fagor 8025M controller. And, the controller on the 3axis CNC Ganesh mill is a Fagor 8040M - same company, just a few versions newer. So, much of what I'm learning on the router will apply (and flatten the learning curve) to the Mill. That was kind of convenient! You'll see more of this toward the end of 2012 and into 2013 - I suspect.

5. FWF Update - In the past few months, there has been some things happening at GearedDrives. Larry, who worked for Bud and Phylis, has taken over as moderator of their Yahoo Groups site. Some of their builders are discussing their installations, etc. But, no word yet on what will become of the company. In order to plan ahead conservatively, I've taken some time to follow up on some suggestions from some of my "advisers" and I've looked into the company called EPI again. I had checked out their website several years ago, but hadn't for a long time. Well, now I think it will serve me well to investigate this as a resource for possibly obtaining a good FWF solution for the Prowler. I have only looked over the information on the website, but I have not contacted the company directly. It's on the list of to-do's. But I'd thought I'd share the info. If any of you have information about EPI and/or Jack Kane - I'd be interested to hear your insight. You can check out their website here: http://www.epi-eng.com/index.html and specifically the PSRU gearboxes here:http://www.epi-eng.com/gearbox_products/gearbox_products_contents.htm
6. Builder Updates:
A. Chuck Has Gotten His Experimental Certificate - Chuck called me recently to report that he got his airplane put all back together after his gear-up landing incident and that he has received his experimental certificate. He still reports that the airplane flies beautifully. He is really impressed with the great handling characteristics of the airplane and it's responsiveness. He's looking forward to taking his wife out on a few short trips soon. Congratulations Chuck! Thanks for the update and enjoy the rides!

B. Bud's Engine Parts Are Fixed - Here is the body of the most recent email that I got from Bud:
"After six months, I finally have my engine back and will begin reinstalling it tomorrow. Along the way, I have learned a lot about Chevy SB engines and mine in particular. I think I know most of what George did to produce it. In a way, I am lucky to have had this opportunity to disassemble and rebuild the engine; I feel more comfortable with it now."
Good Luck with the re-installation of your FWF setup Bud. Please send updates with your progress. And, let me know if I can help in any way.

C. Ray's Engine Work Continues - Ray is continuing to make good progress on his airplane. I was able to make a run up to see him this past week (crew services was leaving me alone for a while - finally). He has gotten a lot of cockpit re-installed to near military specs. The camera blurred a bit, but check this out:

His engine is still apart while he has his heads re-worked, but he's done a awesome job working on the systems and the engine hook-up. Here's some examples:

And, here is his new composite propeller that will grace the front of his airplane. It's a really nice prop, and composite for this application is a good choice.

Unfortunately, Ray is sked for surgery in Jan and Feb. So, it won't be until after his recovery that he will be able to get his engine work completed and run it for the first time. He is estimating at he might get his first runs done in April or early May. I can't wait to hear his plane start. I plan to be there if I possibly can. I'll report with pics and video. Good luck with the surgery Ray. We all hope you recover well and quickly.

D. Roy's Airplane is For Sale - Sadly, Roy reports that he must put his Prowler up for sale. Here is the text from a couple of his emails:
　"I sure hate to have to do it, but I have no choice. I am going to have to put kit# 13 up for sale. If you guys know of anyone that might be interested please give them my contact info. (Please use the Contact page on our website and I will provide the contact info if you are interested). I have included a couple of pictures of the project
I purchased the project about 2 years ago for $30,000 I haven't touched it except for putting it together to look at. The workmanship is very good and I believe its worth the price. The A&P that was working on it has 5 years of full time work in it. It will significantly reduce the build time for the next owner. Let me know if your interested and we can talk further."
Here are the pics that Roy included in his email:

I am really sorry to hear this bad news Roy. I hope your airplane finds a great home! Again, please use the Contact page on our website if you are interested. I will send you Roy's contact info.

E. Bryan's Cranking Away On His Fuselage - Brian sent this update with some pics:
"Any previous builder can sympathize with where i am at with this project... those pesky tail (aft fuselage) skins! Having evaluated all the previous experiences builders have had trying to make this work I decided to English wheel the skins prior to fitment. I have had some success with that idea as the limited number of tie down straps attest. The side skins are troublesome because of their 8' length. Trying to stabilize them while rolling only one edge is unsettling to say the least. The question most asked... Yes, I also had to shim the bulkheads (up to 1/4" in one place) to get a good fitment. So, two steps foreword and one step aft as i discovered i had over tightened several of the hydraulic lines under the cockpit floor. Fortunately I can still lift the floor and re-do those lines before access to that area becomes severely restricted. I would have attached a big red bow for the season but have to run off and ream my motor mounts at a friends house before he leaves for a trip."

Great progress Bryan! Thanks for the pics.

7. XP Talon Info - You might remember that I mentioned the XP Talon in my last blog post. I didn't have a picture of Chuck's unfortunate gear-up incident, but I did have a pic of a similar incident that the XP Talon was involved in. Well, that post prompted an email to me from Vern Goodsell. Vern's a real nice fella. In one of his emails he said:
"I talked to Chuck the day he skidded his Prowler in and we both felt sorry for each other. I had done the same thing two weeks earlier! The Talon is back in the air and flying well. I hope Chuck is close to flying the Prowler but I haven't heard from him.
There is quite a story about how and why the Talon was designed and built but the original owner never finished it. I purchased it in 1997 and worked on it off and on 'til it flew last January.
I always liked the Prowler and actually flew the Jaguar with George years ago. You prowler owners are lucky to have at least some kind of back-up and support, I have the only Talon in the world and no spare parts or support to go with it. But I like a challenge and when something gets bent, I get to work and fix it.
The Talon will be for sale when I finish flying the hours off so if any of you pilots out there are interested, just give me a call or email me."
Thanks for the email's Vern. We're happy to report (above) that Chuck has indeed gotten his Prowler back in the air. Congrats on completing such a unique and beautiful aircraft. It looks like you've done a fantastic job. You never know, maybe 1 of my 2 blog followers might be interested in buying your airplane!?!?

That's all for this update. Thank you for stopping by to check in on us. Merry Christmas from Prowler Aviation. I hope you all enjoy a happy and safe holiday season.

Summer's Over - Finally Some Time In The Shop!!!

2011-10-05T16:40:00.000-07:00

Well, another crazy summer has gone by - and it was a pretty good summer. I've got a lot of items for this update - so let's get started. In this update:
1. Loss of Bud Warren and his daughter Phyllis Ridings of GearedDrives
2. Introducing the "MotionMonster"
3. Making Room In The Shop
4. AirVenture 2011
5. Builder Updates:
    5A. Builder Visit with Bryan
    5B. Builder Visit with Rick
5B. Chuck's Accident
    5C. Bud's Oil Problem
    5D. Steve's Mods
    5E. Nicolas Inventory
6. My Kids Experience EAA Young Eagles

1. Loss of Bud Warren and his daughter Phyllis Ridings of GearedDrives - The experimental aircraft and alternative engine community suffered a great loss this past May. Bud Warren was the owner, designer, and chief technician of GearedDrives, a company that makes a PSRU (and FWF solutions) for experimental aviation alternative engines. His daughter Phyllis was his business partner and assistant. The were both fatally injured in a crash of a customers aircraft. Here is the NTSB's preliminary report:
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20110505X90031&key=1
As you might recall, I built a Prowler FWF mock-up using a full size mock-up of Bud's PSRU to see if it would fit into the un-altered Prowler engine compartment. It will work and I was really planning on using the GearedDrives FWF solution to power our Prowlers. This plan is now on hold pending the disposition of GearedDrives. I have been told that there are at least 2 individuals that are insistent on keeping the company going.  Time will tell.
Regardless the final outcome, we are saddened by the loss of these two wonderful individuals and we would like to convey our condolences to the family and friends of Bud and Phyllis.

2. Introducing the "MotionMonster"   -  After searching for months, I finally found the next machine for Prowler Aviation. It is a 4' x 8' CNC router system that was built by a company called MotionMaster. Since this machine is pretty large (13'x8.5' and 5 tons), we have nicknamed it the MotionMonster.  MotionMaster no longer exists, but there are quite a few of there machines still out there, both in use and for sale at used equipment dealers. I purchased mine in a liquidation sale from a specialty plastics company in San Bernardino, CA in an "as is, where is" condition. This caused a very impromptu, 3-day excursion to get the machine and haul it back to the shop. Here is the machine as it sat in the plastics shop before the move:

Here are some pix of the move:

Here is the MotionMonster after about a 10 days of reconstruction in the shop. The work required to get the machine to this point included; days of searching info online, 3 days of tracing individual wires, splicing a GOB of wires, building an RS232 patch cord and loading laptop software to talk to the controller computer, reformatting the X and Y axis servo controllers, cleaning and lubing X, Y & Z linear motion components, remounting the spindle, more days of reading the controller manuals (installation and programming), etc., etc., Here's the pic:

It's taking a lot of work to get the machine ready to make Prowler parts. From above, the list of repairs and modifications to the machine are pretty numerous. Also, there was not much information available online - so I have had to rely on help from various machining message forums for help getting the machine set up correctly. You can read the more complete info on the work in these threads:
a. http://www.cnczone.com/forums/commercial_cnc_wood_routers/129173-anyone_have_any_motionmaster_documentation.html
b. http://www.practicalmachinist.com/vb/cnc-machining/home-search-offsets-question-230940/
c. http://www.practicalmachinist.com/vb/cnc-machining/help-8025m-tool-change-subroutine-230672/
d. http://www.cnczone.com/forums/fagor_automation/133869-help_8025m_tool_change_subroutine.html

So, at this point the machine is operating in X, Y and Z axis (servos). However, I have not run the spindle yet. The machine was designed to operate on 460V 3 phase power, but I only have 220V single phase power in the shop. The most important components needing the 3 phase power are the spindle and the vacuum table motor. I am now re-wiring the power distribution panel to operate all of the machine's components on 220V 3 phase power. In order to do this, I also need to finish building a 20HP rotary phase converter. I've purchased the components for the RPC and I just need to put them together. Here's the idler motor and the RPC controller:

Put these two together and you get a RPC that will power the spindle and the vacuum table motor.

Here is a pic of the table moved to its (hopefully) final position in the shop:

This re-arranging of the machines in the shop to make room for the MotionMonster has gotten the shop a bit over-crowded - which leads to the next topic.

3. Making Room In The Shop - The last few days in the shop were devoted to trying to get several projects out of the shop that have been "hanging fire" for too long. I was finally able to sell my 1st metal lathe that was replaced with a larger, more capable machine last year. So, this went out the door this past week:

Craigslist is great! Then, I worked on getting the 8ft sheet metal brake ready to list. Here it is all ready to go - no calls yet though:

The last project completed before this commute back to work for a week was the mobile parts bin rack that has been taking up space in the shop for about 3 years. Finally got the shelves and bins put in.

Now it needs a coat of paint and then it will go out in the shed until I can find something else to get rid of in the shop to make room for it back in the shop.

A tool that will not be leaving the shop is the 8ft press brake. I was actually working on designing and building a back-gauge for it when the deal for the MotionMonster popped up. So, that hanging project is next on the hit list. Well, it might be worked in conjunction with the RPC and getting the spindle powered on the big machine. Here's a couple pix of the press brake DRO installations:

If the DRO's look a lot like cheap Chinese digital calipers (with the calipers cut off) from a place with initials HFT - then that's 'cause that's what they are! These will allow precise control of the amount of plunge with the upper die. The depth of the plunge is what will determine the angle of the bend in the lower die - it works like this:

This drawing represents a 90 degree bend in the 0.040" piece of 2024-T3 with a 10 degree over-bend to account for spring-back of the material. After some research I've found that a change of just 0.003" (three thousandths of an inch) will change the bend angle by 1 degree. So, you can see that if I want to make accurate and repeatable bends, I have to have a digital method of measuring the plunge of the die while making the bends.
Here's the beginning of the back-gauge installation. There will be a long piece of rigid aluminum tubing that will be mounted onto the brackets you see here. This will allow for accurately setting the flange size when bending the long pieces of aluminum for the outboard spar web channels, the fuselage longerons, etc. etc.

I hope to have this machine stripped down, cleaned, painted, re-assembled and ready to use in the next month. The outboard spar channels will be the first parts made in this press brake. But, before they can be bent-up in the press brake they will need to be cut on the MotionMonster. The goal is to get the spar channels cut and bent up by the end of the year. My next two weeks in the shop will be busy.

4. AirVenture 2011 - I was able to make it to Airventure again this year, although it was only on Mon-Wed this time. As always, there was way more to do than time to do it. Monday and Tues were beautiful and it only rained a significant amount on Wed morning. Bryan and I were able to get together with Rick again this year for a short while and talk Prowlers. We also tracked down several Prowler parts for Bryan. There were LOADS of Naval aircraft there all week for the Centennial of Naval Aviation celebration. Monday was the tribute to Bob Hoover day. Our girls found this parked on the new Warbirds Ramp:

Areoshell Square (it's actually called something else now - but I can't remember what that is) was "littered" with Burt Rutan airplanes. Wed was tribute to Burt day. Here's my favorite:

This was a first for me:

Overall, it was a great show. And, as the saying goes: Even the worst day at Airventure still beats the best day doing ANYTHING else.

5. Builder Visit and Updates:

5A. Builder Visit with Bryan - After my annual trip to Orlando for recurrent training this Sept, Bryan and I planned a builder visit. I'd seen his airplane for years in pictures, but I wanted to see it up close and personal. Bryan and his wife Lee were wonderful hosts, and we had a great time talking Prowlers for a few days. He is doing a great job on his build. Here is a shot of his tailwheel section with the tailwheel strut that I had built for Bryan about a year ago:

Bryan has been able to incorporate some fixes to the Prowler design that the previous builders have warned us about. He has also recently confirmed several of these while trying to fit-up the aft empenage area. I will attempt to incorporate much of this into the new Prowler design (CAD drawings). Here's an example. It's not a great pix, but several of the builder's have found that the Elevator frame must be made smaller. They are finding that the elevator is rubbing on the aft end of the vertical stabilizer skin and that they have a reduced amount of rudder swing. This pic is pointing at the inboard rib of the elevators to remind me to move it outboard by about 1/4":

The old radiator door operating system was a rather large collection of torque tubes and linkages all connected together to operate the two radiator doors with one motor. Bryan has incorporated the use of small linear actuators that are electrically controlled. It is a wonderful design and it greatly reduces my production parts count. Overall, it's a great improvement. Here's an external pic:

Here's another example. Bryan and I discussed the possibility of taking the largest fuselage former just aft of the cockpit and tipping it aft just a bit to allow for a little more room and a little more reclined seating of the aft pilot seat. Well, he's doing it! I'll be watching closely on this improvement to see if I can incorporate it into the new Prowler design without having to change and/or re-design a huge number of parts. We'll see how it goes. Here's a pic:

One other change that Bryan has incorporated is the elimination of the inner gear doors. Every builder has commented on how complicated, intricate, and futzy they were to build and operate. So, Bryan has opted for a B737 style setup with outer gear doors and brushes about the wheels. It will look great. Whatdaya think?:

Overall, Bryan is building a beautiful airplane. The design is well thought out and the workmanship is impressive. It will be a great airplane. Here's an overall shot of the plane in his garage:

Here's a shot of the Davies Estate:

You have a wonderful home Bryan and you are doing a excellent job on the Prowler. Thank you for your hospitality. I really enjoyed the visit and meeting the family again.

5B. Builder Visit with Rick (The RW&B Prowler) - While I was visiting Bryan, he coordinated an opportunity to meet with Rick and see his airplane. You might recall that Rick bought Kit #13 and the first production Red, White and Blue airplane. I've also seen this airplane in pics for years, but it was a real treat to get to look it over, up close. Here's a pic:

Here's a shot with yours truly:

It was interesting, although probably not unexpected, that much of the airplane is very, very similar to George's current airplane (the gray and black Kit #5). As we were looking over the RW&B plane, Bryan and I noticed that the inside edges of the elevators had been worked down, with material removed very close to the rivet line where the elevators meet the aft edge of the vertical stab (sound familiar). So, apparently this is not a new problem! I can assure you that this will be fixed in the future though. Here's a pic of Bryan looking over Rick's other airplane - a very well appointed Falco:

That is also a very, very nice aircraft. Thanks for letting us drop by and check out your airplanes, Rick. I really appreciate you taking the time to make this possible. I learned a lot and really enjoyed seeing more of the history of Prowler aviation.

5C. Chuck's Accident - I am really sorry to report that on one of Chuck's phase 2 flights of his Prowler he performed a gear-up landing. He freely admits that he just plain forgot to put the gear down. I talked to him shortly after he started tearing down the PSRU and the engine to inspect if for damage. He reports that there was no detectable damage to any of the components (up to that point in time). However, out of an abundance of caution, the were creating a list of items to replace. According to Ray, Chuck started working on repairing the radiators pretty quickly. Chuck visited Ray at one point to get a hand with some of the radiator work. Unfortunately, I don't have any pics to go with this report, but I have to imagine that this scene must have looked something like this:

This was actually an XP-Talon that was being flown by it's builder and current owner. Here is a link to the FAA incident report: http://www.faa.gov/data_research/accident_incident/preliminary_data/events01/media/34_420XP.txt
There are some that claim that this airplane is a modified version of a Prowler.  You can be the judge. Investigate this airplane via google searches and look over the information. Sorry for the sidebar, but the point of all this is that Chuck can hopefully take some solace in the fact that he is (at least) not alone. Good luck with the repairs Chuck. Please let me know if there is anything more I can do to help.

    5D. Bud's Oil Problem - I got a note from Bud recently telling me that he had spun a main crankshaft bearing in his engine. He had been working on an engine oil modification to his Prowler that he and Steve had researched together online. They were both experiencing oil pressure and temperature problems and found a modification package from a vendor offering a dry-sump system. After finishing the installation, Bud was attempting to test his engine and experienced an oil starvation problem. The net result was a spun bearing. So, he is in the process of rounding up the needed parts and getting the necessary machining done.  Of course, we are really sorry to hear this bad news, but Bud is making good progress to get the repairs done.  Again, good luck with the repairs Bud. Please let me know if there is anything more I can do to help you get your Prowler flying again.

    5E. Steve's Mods - As mentioned above, Steve is working on the same mod as Bud. But, since he is not retired yet, he hasn't had as much time to devote to the mod work. He is, however, still making great progress. Here are a couple of pix of his mod work:

and; a file photo of his airplane in the past:

Nice work Steve! Hope the mods go well for you. Please let me know how it turns out.

5F. Nicolas Inventory - Nicolas has been working on doing a thorough inventory of the parts in his kit. We have exchanged emails and he has shared his list of parts that may need to be located or made in order to make his kit complete. He has said that he will start work on the wing spar first. Please send pictures when you get going Nicolas. Here is a "Before" pic:

And, here are some "After" shots:

Awesome job organizing your parts Nicolas. I will make sure that you get the rest of the parts that you need going forward. Please update me on your progress.

6. My Kids Experience EAA Young Eagles - All work and no play makes..... well you know. So, in May I took the day off from the day-job and the Prowler job and took my family to the local EAA chapter for their Young Eagles day. My kids have flown commercial airlines since each of them were babies, but none of them has ever been up in a GA airplane. So, we decided that the time was right and spent the day with them at my EAA chapter (1148). Here's a pic of our girls with Andrea the YE volunteer pilot:

The girls really enjoyed the day. The discussion at the dinner table that night was how we were going to buy an airplane after we got mom's van paid off. Oh-oh, be careful what you wish for!!
Also, a huge thank you to the YE program and the YE volunteers. It's an outstanding program.

Well, that's all for this update. I realize this is a long update, but I wanted to get this info out there. I will have to try harder to do more of these updates in smaller chunks. Until next time, I hope you all have a great fall season.

Has it REALLY been almost 6 months!?!?!?

2011-05-09T14:22:00.000-07:00

Hi! Welcome back and thanks for checking in with us. Well, we're 5 months into this new year and it's been almost 6 months since the last update – so it's about time for another update. In this one:

1.Builder Updates
1A. Roy Farris (Kit #13) – For Sale.
1B. Chuck Westcott (Kit #12) – First solo flight.
1C. Bud Tedesco (Kit #16) – Mr. Test Pilot!
1D. Ray Seim (Kit #10) – In The Home Stretch.
1E. Bryan Davies (Kit #7) - Wing's A Home Run – Fuselage On-Deck.
1F. Steve Rogers (Kit #14) – New Engine Oil System.
1G. George Morse (Kit #5) – Still For Sale.
2. CAD Progress - Done with the “First Pass”
3. That &*@#$!% Sheet Metal Brake -
4. New (Home Brew) 8 Foot Press Brake -
5. CNC Plasma to CNC Router -
6. Great Wall of Prowler -
7. Heat Treating of Horizontal Stabilizer Parts -

Let's start with the builder updates,

1.Builder Updates – Here is the latest information from the current builder's:
1A. Roy Farris (Kit #13) – The Economy. Sadly, Roy reports that the economy has downsized his job. He initially thought he'd be forced to put his Prowler up for sale. But, as of our last contact with Roy, he is working on a deal that will allow him to keep his Prowler. Here's a file pic of his airplane:1B. Chuck Westcott (Kit #12) – First solo flight. Chuck called a few weeks ago just after his first ever flight in his own Prowler. Until now he has had a “hired hand” doing the test flying of his airplane. He decided that having flown nothing but “Whales” (B747's) for most of his career – it just might not be prudent to jump in his Prowler and do his own test flying. However, after some tail-dragger time in a Citabria he was comfortable enough to take the Prowler out on his own. He reports that the 20 years of work it took to get the plane done was worth it. He was VERY pleased with the airplane. He reports that it is very stable, very responsive, and very fast. Even without a supercharger, right after takeoff his plane was doing nearly 200 knots before he knew it. He reports that the Prowler is very easy to land and very stable throughout the approach. On a follow-on flight he got a low oil quantity indication and made the flight a short one, just to be cautious. But the plane flies great. He is now working to discover where the oil is going.
In any event, GREAT JOB CHUCK! We are all very happy for you. OK, we're all a little envious too! Thank you for sharing your experience and reporting on your flights.

1C. Bud Tedesco (Kit #16) – Mr. Test Pilot! OK Bud – you're just having too much fun with this test pilot thing! Got an email from Bud recently – and I quote:

”On T/O today, I hauled the nose up to keep the A/S below 100kts until the gear was retracted. Glancing at the A/S, I noted that it read 0 (zero), but we were climbing like a homesick angel. The brilliant deduction was "sum ting wong". By dint of superior airmanship, skill and cunning (otherwise known as blind luck), a successful landing was accomplished. Neither the air vehicle nor its occupant was dented.”

As you may recall, on one of Bud's previous test flights his canopy departed the aircraft (quite a story). Hence, we think that Bud might be taking this test pilot thing a bit too far (kidding). In all seriousness, nice work Bud. Turns out that the dynamic pressure line to his pitot-static system had vibrated to the point of separation at the top of the pitot tube and this caused the loss of airspeed indication. He urges everyone to ensure that their dynamic and static pressure lines are well supported (and damped) to prevent this. Great use of those partial panel skills you learned all those years ago! In addition, Bud reports a few gripes that he is still working to resolve on his airplane. One is a heavy left wing. He has added lead weight to the right wing to counter this (for the time being) until the root cause of this asymmetry can be investigated more fully. Bud has now completed more than 10 hrs of flight testing so his radius of operation has opened up to 75nm (from 25nm). More to follow. Nice work Bud, but next time maybe just report a “nominal” test flight – for something different (;-).

1D. Ray Seim (Kit #10) – In The Home Stretch. Well, the “Master” is still hard at it. Ray has gotten his fairings made, installed, and primed. Check these out! Ray had them hand made by Will, a professional metal smith near Van Nuys Airport. They turned out fantastic:He has also been finishing up the myriad of small items that pop up as you get closer to the end of a project in a effort to get ready. I recently visited Ray just after he finished his exhaust stack fairings. By now Ray should be getting deep into the final engine work. He was just waiting for one of the supercharger pulleys to show up with the UPS guy so that he could start the final install of that. Great work Ray!

1E. Bryan Davies (Kit #7) - The Wing's A Home Run – The Fuselage is On-Deck. Bryan has been moving right along on his airplane. He has recently completely finished up his entire wing section (center and outboard sections). All the systems are installed and tested including the fuel, venting, hydraulic, landing gear, brakes, and associated electrical systems. Here's an earlier pic of his wing section:Bryan sent me this pic just last week. He has fabricated his fuselage jig and started to place his fuselage formers:Nice work Bryan! You're doing a first rate job of building your Prowler.

1F. Steve Rogers (Kit #14) – New Engine Oil System. Our most recent email from Steve says that he is in the process of re-designing much of the engine oil system of his Prowler. He is creating a new lower cowl piece that includes a chin inlet and a new diffuser. It will hold a new style oil cooler and incorporate exit ducts. He is also switching to a complete scavenging system with three scavenging pumps and an air/oil separating tank, as well as a remote oil filter mount with a built-in temp sensor port and a pressure port that he will use as a source to lubricate the supercharger. Here's a couple of pics:Here's a pic of Steve's airplane:Nice work Steve. We hope you get a great system improvement and anxiously await the results of your work.

1G. George Morse (Kit #5) – Still For Sale. George's airplane is still for sale. George completed the annual late last year and has it in flying condition. There have been a few “lookers” but no serious inquiries to date.

2. CAD Progress – Done with the “First Pass.” We've now completed our first pass through the entire airplane and have at least one CAD drawing of each part of the airplane that we got from George. Since we were sort-of learning as we went along in the CAD drawing process, the work at the beginning was not of the same quality as the recent work completed. So, the “second pass” work has now started. This next pass will help to “standardized” the drawings, correct errors and use more accurate techniques in developing some of the drawings. Here's a 3D pic of the cockpit floor area:
3. That &*@#$!% Sheet Metal Brake - Well, after another three days of tweaks, the 8 ft sheet metal brake project is a success and a failure. Here are some pix straightening the bed:Here are some pix straightening the clamp:Here's adding a stiffener to the horizontal part of the clamp:Here's the finished product (in paint):We've gotten the brake to successfully bend 16 ga. steel sheet. But trying to use the brake to bend 2024-T3 does not give acceptable results. Despite the addition of extra stiffeners and stiff-backs, the stiffness of 2024-T3 just doesn't allow it to be bent well on this sheet metal brake. We decided to give up on the apron type brake and pursue a press type brake.

4. New (Home Brew) 8 Foot Press Brake - After some research and homework on press brakes, we decided to give a press brake a try. A commercial unit that will bend 8 ft would be cost and size prohibitive for the current Prowler Aviation. So, we decided to try a “homebrew” solution. Here's the base:Here's the basic frame:Here's the upper die machining:Here's upper and lower dies installed in the press:You may notice that the brake is currenly powered "manually." This will be replaced with a real hydraulic system eventually. Now that the fabrication of the basic machine is complete, the next steps are to mount a digital plunge measurement system and install a backgauge system. Once these steps are done the test bending can begin. The test bends will calibrate both the plunge depth .vs. bend angle and backgauge system (for specific flange sizes). This machine will be used to bend many of the parts of a Prowler. Eventually, we hope to use it to bend longerons, floor channels, outboard wing spar channels, wing leading edge skins, aft fuselage skins, and many more. We hope that it will become the new Prowler "multi-tool."

5. CNC Plasma to CNC Router - After spending significant time, energy and money on rebuilding a Torchmate 1 plasma table into a system with CandCNC electronics with a Digital Torch Height Control, we discovered that it cannot be used to cut aircraft aluminum. Turns out that when you use high heat to weld or cut aluminum it creates an area called a heat affected zone (HAZ). What makes 2024-T3 so stiff is the copper that is alloyed into the aluminum. But, in the HAZ, the heat makes the copper come out of solution and form "clumps" that lodge in between the grains of aluminum. This reduces the metals ability to resist corrosion, in particular a corrosion know as "Inter-granular Corrosion."
So, we are now pursuing the purchase or building of a CNC routing system. A CNC router that is at least 4ft x 8ft will allow us to cut out any and all of the Prowler parts. It will also allow us to pursue the process of "match drilling" of part holes. This has the potential to greatly improve the building experience by simplifying assembly process. More to follow.

6. Great Wall of Prowler - It's the time of year again in Northern California that the ground can be worked and the weather is not too hot. So we took advantage of some available time to get the retaining wall completed in front of the shop. It took a little over a week and we completed the wall as far as we've planned to for this year. Because the wall is getting fairly lengthy, we've jokingly coined it the "Great Wall of Prowler". Here are a few shots:
7. Heat Treating of Horizontal Stabilizer Parts -
We've had several parts of the Horz Stab setting on the bench for quite some time now. Mostly, this section of the plane has been waiting on getting 8 parts heat treated from the 2024-O material to the T4 condition. While sitting on-call down in the LA area, we found a company that is seriously all about heat treating aluminum. Newton Heat Treating in City of Industry, CA does an amazing array of functions related to heating and treating aluminum; Plus they're just great folks! Here's the parts that we had treated and a shot of the front of Newton's facilities:For now, we'll continue to develop production processes and push toward future production of Prowler kits. The goal for this year is to get the entire wing spar into the wing jig. While this goal may sound fairly simple, the fact is that in order to accomplish this, we will have had to complete and test many production processes. These are the processes that are necessary to make parts that are necessary to make not only the wing spar parts, but also much of the rest of the airplane. So, accomplishing this will help to speed up making parts in the future. That's all for this update. I'll try get back to updating a little more often, as it makes the updates shorter and easier to do.

Prowler Year End Wrap-up

2010-12-08T14:40:00.000-08:00

Hello Again,
Thanks for stopping by to check in on us here at the new Prowler Aviation. There has been a fair amount of news since our last post, so lets get started. In this post:

1. CAD Work Continues
2. New FWF Mock-up Update
3. Builder Updates
3A. Ray Seim (Kit #10)
3B. Nicolas Hombruex (Kit #11)
3C. Chuck Westcott (Kit #12)
3D. Bud Tedesco (Kit #16)
3E. John "Cabi" Cabigas (Kit #17)
4. George Is Back On His Feet
5. Looking Ahead

1. CAD Work Continues - We're back on the CAD horse again here. We just finished CADing out the Main Landing Gear. Here's a pic of the 3D composite drawing. Keep in mind that for each separate colored piece you see here, there is a full technical drawing with a 3D representation of that part stored in another file. This picture is a collection of all the the 3D part representations all gathered together in one place, with all parts then placed in the correct orientation relative to each other.
This main landing gear is going to be, hands down, the most complex and expensive part of the Prowler Kit. The retractable landing gear adds a huge level of complexity when compared to most kits out on the market (both in pieces to produce and systems to make it operate). This is where the new Prowler Kits will be "make or break." By this I mean, if we can find an efficient, practical and cost effective way to make these parts - the kit might still be affordable enough to make a go of it. That's where all this CAD and CNC stuff comes into play. If we can make production computer controlled, make it repeatable, and make it (fairly) simple - it just might be a successful endeavor. Time will tell.

2. New FWF Mock-up Update - We've completed a little more on the new FWF mock-up introduced in the last blog update. The most notable new portion of the FWF mock-up is that the engine has been moved back 2 inches and a 2 inch prop extension was added. This was necessary to gain clearance room in the lower forward area of the new PSRU. Geared Drives has confirmed that this extension is acceptable. Also, the stand to hold the engine in place has been completely re-designed. By making the stand more narrow, it is now able to hold the engine in the correct location and still allow the engine cowling longerons to be placed where needed in order to finish the mock-up later. Also new is the change in the upward sweep of the lower longerons (and eventually the skins) to more closely replicate the original Prowler look. Here are few updated pix of the FWF mock-up:Also new since the last post are the upper and lower longerons themselves. I am still waiting to fabricate the side longerons until I can better define what the new exhaust system will entail. There are some issues to sort out relative to the type of exhaust system, the location of the exhaust system, etc. I don't want to spend time and effort to fabricate something only to have to tear it off and start over again (when I figure out,or stumble across, a better design for the exhaust). So this part will remain open for now.
BTW - the exhaust pipes you see in these pics are the ones that George used to test run his engines after assembly. They are much longer and more steeply pitched down than what was used on the current kits. I just put these on to help give some reference, and to use as a basis to start from in considering the new exhaust system.
We are also just beginning our initial discussions with Geared Drives on developing this as a FWF package for them. So far Bud and his crew have been very positive about the Prowler. More to follow.

3. Builder Updates - I have several builder updates to share this time. Some I have new pix to share, some I only have the information - but the news is generally very good and great progress is being made on many fronts. Here ya go (in Kit # order):
3A. Ray Seim (Kit #10) - In early Sep this year, I was able to help Ray mount his engine on this airplane for the first time. By late Sep he had completed some of the initial, basic plumbing hook-ups. Here's a shot: By late Oct, Ray had completed fitting his entire engine compartment and was ready to pull the airplane off the fuselage jig. Here's a pic of Ray and I working on removing the airplane from the jig: And here is a pic of his airplane sitting on it's own gear for the very first time: Here is almost the same shot a few days later with the mostly completed engine compartment installed: Ray does outstanding work! The airplane is currently in Van Nuys, CA having the fairings put on by an expert sheet metal guy. Ray decided to pay to have this part of the airplane completed for him, instead of trying to learn the art of this type of compound bending and working of sheet aluminum. Here's a pic of his templates and fairing lines on the airplane before shipping to Will's shop: It will, no doubt, look awesome when it is done.

3B. Nicolas Hombruex (Kit #11) - The Prowler Kit is now certified in France! Nicolas sent an email recently telling us that the French government has approved him to build the Prowler kit. In his own words:

Hello my friends. Here is my good news. I get a good
email: (11/26/2010):

Suite à discussion avec Mr Hombreux pour répondre à
mes interrogations, la DGAC émet un avis favorable à
l'éligibilité au CNRA du Kit US du Prowler qui peut -être
considéré comme lot matière.

Jean-Marie KLINKA
Project Certification Manager
DGAC/DSAC/NO/NAV

So now the Prowler aviation Jaguar's "kit" is allowed in
France!!!!!!

That's great news! Nice job Nicolas. Here are a few pix of some of Nicolas's kit shortly after he received the shipment that was arranged by John "Cabi" Cabigas.Nicolas tells me that he can now start working on his kit with the knowledge that it will be accepted in France and given an aircraft certificate. We look forward to supporting your efforts Nicolas. Congratulations!

3C. Chuck Westcott (Kit #12) - Chuck called a few weeks ago and reported a very successful follow on test flight for his Prowler. He reported that the airplane flew very well, all systems were working well, and the engine was running great. That is GREAT news after the troubles that Chuck has gone through recently with his plane.
He commissioned a very knowledgeable gent from the area to help him overhaul his engine after he started having serious engine trouble approx 18 months ago. They tore the engine down and started over essentially from scratch. The short story is the airplane now has a completely rebuilt LS1 engine with an improved PSRU (new bearings). The most notable improvement was the ignition system. After much research, they determined that George's original ignition system was not very robust and has the potential to ground itself out under some situations. Chuck's engine guy figured out a workable solution and I have distributed that information to all kit owners via our prowler builder's yahoo group. It has apparently made a significant difference in how well the engine now runs. Here's a file pic of the engine work in progress:
Chuck is now going to have Keith finish flying off the 40 hours for the experimental certificate. Good Stuff. Thanks for sharing the helpful information Chuck. Congratulations on a large step forward on your airplane.

3D. Bud Tedesco (Kit #16) - Well, Bud has the most incredible Prowler story so far. About a month ago I got an email from Bud explaining that while on test flight #4 the canopy departed the aircraft at approx. 5,500 ft and about 200mph! Nope, no joke! But that's not the amazing part. When he got the airplane back to base, he called and informed the Sheriff's office in two counties (BTW - he reports that the airplane flies very nicely "sans canopy"). Later that day, one of the Sheriff's offices called and told him that a farmer had found the canopy in a field! But wait - the story gets even better. When he picked up the canopy it APPEARED ALMOST COMPLETELY UNDAMAGED!!!! Turns out that the canopy apparently landed inverted and down on the forward end. This caused the canopy frame to be sprung outward in the forward portion. Using some undisclosed magic, Bud was able to "massage" the canopy back into shape and it is being re-installed on the airplane. Amazing!
Bud has the only Prowler, to date, that has a sliding canopy. The cause was determined to be the latching mechanism on the aft of the canopy. The forward part of the canopy is held by a flange mounted on top of the windscreen frame. The front of the canopy slides into/under this flange in the front and then the aft part of the canopy drops down and is held in place by pins into pillow blocks mounted to the canopy frame. There is a detent used to hold the aft latches in place when closed, but it had apparently vibrated out of the detent allowing the aft to pop loose. The canopy then only had to slide aft a short distance and it departed the plane. The only other damage was a short slice in the fuselage skin in the baggage compartment area on the right side of the aircraft.
Here is a file pic of Bud's airplane shortly after he moved it out of his basement and into it's new hangar this spring (the date on this pic is not correct - it is probably more like Apr/May of 2010).That is an AMAZING story Bud. Awesome job on getting the aircraft, pilot and pieces all back down and back together safely!

3E. John "Cabi" Cabigas (Kit #17) - Cabi recently sent me some pix and a movie showing his plasma cutting system making his main wing spar cap strips. Here's a sample:
Cabi reports that the plasma works well on the .160" 2024-T3 material for the spars. That's good news. I have only tried 0.040" 2024-T3 so far (while cutting blanks for the FWF mock-up longerons), but I've been very pleased with the results. Good news for future Prowler Production. NICE JOB Cabi and thanks for sharing. Now get retired already so you can really get after that Prowler that is lurking in your garage and hangar!

4. George Is Back On His Feet - I am very happy to report that George is recovering very well from his broken femur surgery. In fact, I went to help him drag the airplane out of it's new home at the Red Bluff, CA (RBL) hangar a few days ago. The airplane hadn't been run in a while and it was a nice day - so we got it out at fired it up to circulate some fluids around in the motor. Before he fell recently, George had completed the annual on the airplane and got it back to airworthy condition. There have been a few lookers, but the airplane is still currently "For Sale." Here's a file pic from last year's Redding (RDD) airshow:

5. Looking Ahead - As 2010 becomes history, we're trying to set some loose "goals" for the new Prowler Aviation in 2011. Here's what stands out so far:

First- GET THE MAIN WING IN THE JIG. We've got to get set up with a sheet metal brake that works. The 8' sheet metal brake project from earlier this year has not paned out so far. Initial attempts to bend anything heavier than flashing material have resulted in poor bends. The brake isn't currently rigid enough to handle bending 0.040" 2024-T3. I'm surprised how tough and starchy this material really is. I think that it actually bends harder than mild steel. Here's a pic of the brake when we were working on it earlier this year. We'll try one more time to add some plate and beef it up, but if it doesn't improve it will end up out the door and we'll purchase a good machine:Once we get a good working sheet metal brake, we can bend up the outboard wing spar channels and proceed to mount the center and outboard wing spar components into the jig. That will eventually (probably in 2012) give way to producing the wing ribs to place onto the spars.

Second - Continue working on the FWF mock up. Next step is to design and build the motor mounts that will be used with the Geared Drives PSRU and then put those on the mock-up to see how they fit. Then finish researching the exhaust system and complete the cowlings.

Third - Continue to complete the CAD work for all of the parts of the Kit that will be produced by Prowler. This work also lends itself to future assembly manual work - as these 3D representations will make valuable pictures to help describe the "how to" of kit assembly. With the CAD work completed we will also be able to begin learning the CAM techniques to take these drawings and start using the CNC mill to make some landing gear parts.

That's all for this update. Thanks for stopping by to see our progress.
We wish all of you a health and happy holiday season.
And, we look forward to seeing you all back again in 2011.

CAD Burnout - But Progress Continues!

2010-10-08T09:49:00.000-07:00

Welcome Back! Thanks for checking in on us.

Well, after working on CAD drawings of Prowler parts for what seems like every spare minute of my life during the past year - I've officially reached burn out. But, that doesn't mean that progress towards production is halted. It just means we needed to strike out in a different direction for a while and do something a little creative - to keep the motivation level high.

In this update:
1. OK, Still Doing some CAD work
2. CNC Plasma Fixes
3. Ray's Prowler is Getting Its FWF
4. The New Prowler FWF Solution & Mock-up
5. Builder Progress Reports
6. Future Home of Prowler - East
7. Update on George

Here goes:

1. OK, Still Doing some CAD work - While CAD burn-out is evident, it has almost become a way of life, so the Prowler Part count-down does continue. The Flap Sub-kit is now complete and the Main Landing Gear is about to start. In addition, I have also had the opportunity to CAD up several parts to use in fabricating the new Prowler engine setup. See the next item for more of this. There have also been several CAD jobs for various parts that have come up in association with builder requests. So, we are staying CAD "proficient" thru the doldrums.

2. CNC Plasma Fixes - We found that while cutting round parts with the Prowler Plasma machine, perfect circles were coming out with two flat sides. Investigating the cause of this lead to some side-tracks and an eventual solution. Turns out, the flat sides were happening where the X axis was changing directions during a cut. Checking into the mechanical aspect, it was found that the gear rack on the X axis had dropped down and there was too much backlash in the gears. While fixing that, I found out that one of the studs that held the gear rack had broken off in the frame and was just rolling over when trying to tighten it. So, off with the gear rack and out with the MIG welder. Problem solved, until the gear rack bumped the gantry and the actual gear track section (all 4 feet) popped right off the rack. So, that lead to researching how and why this gear track was bonded to the rest of the rack. After, finally, finding the special Loctite product used to bond this track to the rack, it was fixed (actually re-bonded all 8 feet just for piece of mind). Here are a couple of pix of the re-bonding:
With the gear rack re-installed the problem was still there. Circles were still coming out with the two flat sides. So, assuming all the mechanical possibilities were covered, the problem had to be in the electronics. While testing one time, I noticed the table visibly shaking while simply running the X axis in a (presumed) continuous, constant speed move to the right and/or left. We ran some more tests and figured out that the X axis (stepper motor) was missing steps badly. After swapping motors, driver cards, and inputs we eventually logically deduced that the X axis motor driver PC card was at fault. After a bunch of research (again) we ordered and installed a new card:Problem solved! Since then, we have cut several parts with no problems. Here are some pix of parts cut out for another item in this post (FWF Mock-up) discussed below.

The plasma cutting table seems to be getting much more reliable and/or the operator is getting better. In any event, it definitely makes fabricating specialty parts a breeze.

3. Ray's Prowler is Getting Its FWF - Ray is making really good progress on his Prowler lately. During the past month I've visited him several times and even got to help him hang is motor during one visit. Check it out: The next visit, Ray had added several of the various plumbing lines and other connections: Since then, Ray has added several of the engine compartment framing pieces and the spinner attachment parts:Ray plans to have the engine cowlings on and fitted by the end of Oct. Then the plane will be trailered up to his sheetmetal guy to fabricate and fit all of the complex and compound skin parts (wing root fairings, etc.) Nice work Ray! Thanks for letting us be involved with your progress. The Plane is looking GREAT!
4. The New Prowler FWF Solution & Mock-up - All this work with Ray on his FWF, combined with the CAD burn-out, got me thinking about the new Prowler's FWF system. We have decided that the new Prowler Aviation is not going to be in the engine building business. At least, not initially. Getting the airframe finished will be challenge enough. George's engine system, while appealing, is just not practical. It requires a massive amount of mill, lathe and "gear-head" work to get one working FWF system. With Ray constantly telling me that "You need to get the build time down!," it is very apparent that the old way isn't going to work.
So, here is the FWF plan for the New Prowler: Order a stock crate LS1 engine with computer harness, add one Geared Drives PSRU system, top it off with a (yet to be determined) propeller and hub combination and go fly. (At least in theory.) We have been watching Bud Warren and his Geared Drive system for years and we're convinced that it is the best overall solution for the Prowler FWF - if it will fit! If it does, you just might see the Prowler listed with the rest of Geared Drives FWF packages. Check out their website at the link above.
So, will it fit? There-in lies the catch. The only way I know of to prove it is to mock-it-up and see if the original Prowler engine compartment components will fit around this new system. If not, it will make it easy to see what changes will be necessary to make it fit. I also thought that it would be a good time to tackle this with Ray working on this part of his airplane. By sort-of paralleling what Ray is working on, I can benefit from him allowing me to help with airplane. I've already collected tons of data, measurements and part information. I even found out there are parts of this airplane that I didn't know existed - Humph! But with a little help from our friends, we'll get it all together.
OK - I don't know if there is a standardized way of doing a FWF mock-up, but here's what I've done:
A. Collected damaged, broken, and worn-out parts of an LS1 engine:
B. Build a cart (so you can move things around in a shop that is starting to get pretty full!) C. Put the engine parts together and put them on a stand that can be used to move the engine in six degrees of freedom as needed:

C. Research the Geared Drives system and make a mock-up of the PSRU. Thankfully, there is just enough information available on their website to be able to CAD up the necessary parts to build a full-scale mock-up.
D. Add very contrasting paint: E. Cut out, paint and and add flanges to a firewall: F. Put it all together: In the next week, I'll be adding as many other engine compartment components as possible. Cabi and I will be getting together to fabricate the "horse collar" that attaches to the motor mount and makes of the forward framing that the engine cowling skins attach to. I'll also be adding longerons and eventually skins - although that will require the purchase of, and learning how to use, an English Wheel. That might take a bit more time.
So far, what is evident is that the engine will sit at least 3 inches lower than it does in George's design. This is a result of the Geared Drives design has the prop output shaft centerline 3 inches higher than George's design above the crankshaft centerline. Since the engine in the Geared Drives design sits opposite to what it would in a car (George drove his PSRU from the front of the engine), the rear sump oil pan might get too tight. This could require a switch to a front sump oil pan, which would put it in the back of the airplane engine.
So, there it is. There will be more to follow, but initial indications are that this new FWF will fit in the old Prowler engine compartment, with some minor changes.

5. Other Builder Progress Reports - Here is a quick run-down of the recent info I have on current builders. Some of this info is third hand, but from reliable sources.
A. Chuck Westcott is still working on ignition issues. His engine man has been busy with some other projects, but work continues and he plans to have his Prowler flying again soon. He wants to get the 40 hrs flown off and then the plane will go up for sale.
B. Bud Tedesco - Still working on the gripe list from the first flight. Hope to hear about a follow-on flight soon.
C. Steve Rogers - Has flown his Prowler a few time this summer up in SEA area. He has most of his gripe list taken care of and the plane is working well.
D. Bryan Davies - The day job has stepped it up a notch or two, so he's been working a bit more. However, he's working on building the fuselage. He also, finally landed a deal with the Delta Hawk guys and has put his deposit on his new engine.

6. Future Home of Prowler - East - Dave has spent the majority of the past year moving out of the old homestead, moving it all up to the BNA area, moving into a rental across the runway from their future home/hangar, and now actually building the new homestead. Here's a couple of pix:

Yes, that's a grass strip in the background. Beautiful house on a great property Dave!

7. Update on George - Recently, George was working on his 1963 Starfire and took a fall. He fractured his hip and needed to have a pin put in. He has had the surgery and made it back home last Tues. We wish him a speedy recovery.

CAD Work Continues in a Busy Summer

2010-08-16T15:14:00.000-07:00

Hello Everyone,

Thanks for stopping by to check up on us. Well, the busy summer schedule associated with the "day job" combined with summer family activities has kept me out of the shop for almost 8 weeks! Fortunately, for the time being, there is always CAD work to do. It gives me something to do while commuting, sitting on call, sitting in a hotel room and any other long periods of time I spend sitting.

Of course, the biggest news of late is covered in the previous post; The 6th Prowler to fly. I will update again after Bud's follow-on flights. Congrats again, Bud!

IN THIS UPDATE:
1. A New Addition to the Prowler Shop
2. Bryan & Todd visit Ray and his Prowler
3. AirVenture 2010
4. CAD Work Progress

1. A New Addition to the Prowler Shop - The newest news is something that I've been working on for a good part of the summer. I came across a gent that had a 3 axis CNC Knee Mill for sale in his garage about 10 miles from the Prowler - West shop. It had sustained some damage and was sitting on a pallet and hadn't run in several years. To make a long story short, I took a gamble, put in a low-ball offer and bought the mill. Turns out that all the damage was just superficial and visual, but did not affect the functioning of the mill in any way. The only 1/2 day that I've had in the shop since mid June was hooking up the mill and testing it last Friday. Here it is:
Happily, the mill works fine and will be invaluable in making Prowler landing gear parts (or any 3D parts) in the future. We weren't really ready to spend the $,$$$ for this right now, but I was able to get it at such a ridiculously low cost that I couldn't afford NOT to do it now. Another sizable learning curve to conquer! Tally Ho.

2. Bryan & Todd visit Ray and his Prowler - In July Bryan and I both had some time off on the same day in the LAX area. Ray was available that day, so we drove up to see him. Bryan and Ray were able meet in person and it was cool to watch two guys that are very knowledgeable about Prowlers converse and compare their building experiences. Here's a pix from the visit:
Ray's airplane is moving right along. The day we visited Ray, he was just beginning the process of pulling many of the systems out of the cockpit to make room for riveting on the skins on the sides of the cockpit. He should have that done by now and be in the process of re-installing all of the systems. With that complete he will soon be tackling the engine and related systems. Here's a current pic of his panel:
It was a great day and we all enjoyed the visit. Thanks for hosting on short notice Ray.

3. AirVenture 2010 - One word universally sums up AirVenture this year - WET! It rained nearly 3 times the average monthly July rainfall for Wisconsin in the week just before AirVenture. There were large sections of KOSH and the EAA grounds that were not usable and were sectioned off so that planes, trains, automobiles and people wouldn't get stuck in the mud. It made for a fairly disorganized show this year, but the show did go on. It's truly amazing what EAA managed to come up with for alternate plans (on several fronts) to keep the show going, despite the weather. Here's a pic of an impromptu Prowler meeting with (L to R) Todd, Rick and Bryan:
The two highlights of the show for me this year were seeing two beautifully restored airplanes that have never been at any airshow before. This first one is a VERY RARE Royal Navy Spitfire (Carrier Version)!! Yep, with folding wings and a tailhook! There are only 4 known to exist like it in the world, and this is the ONLY ONE that is flying in the entire world! The restoration on this airplane was the best that I have personally ever seen. This is an absolutely gorgeous warbird:
The other airplane was "Kathleen" a newly restored F4U Corsair. My personal favorite. If I could have any plane I wanted - the Corsair would be it! This one is owned by a former TWA guy who bought it from someone out of a jungle in El Salvador in the early 70's. It was restored by Airpower Unlimited in Jermoe, ID. It's a beautiful aircraft:
All things considered, it was a great time. Then again, the worst day at AirVenture still beats any other day of the year - period!!!

4. CAD Work Progress - I think I can safely say that I have about 2/3 of the Prowler parts CAD'ed out. Each part is actually drawn 4 ways: First - a standard 3-view of the part; Second - a flat pattern drawing of the part; Third - a plasma tool path drawing; and Fourth - a 3D view of the part. In addition, I then take the individual 3D part drawings and put them together into sub-assembly drawings (where appropriate). Here is an example of all of the Radiator parts gathered together into a 3D drawing (with one side off):
The colors are there for contrast to distinguish one part from the next. To date, here is the status of CAD work for the Prowler Sub-Kits:
Completed - Vert Stab, Horz Stab, Elevator, Rudder, Center Wing Section Main Spar, Outboard Wing Main Spar, Torque Boxes, Center & Outboard Rear Spar, Center Wing Components, Outboard Wing Components, Radiators, Ailerons, Flaps;
Remaining - Main Landing Gear, Fuselage - Cockpit, Fuselage - Aft, Tailwheel Components, Engine Compartment Components.

At this point, I am hoping to finish the majority of the CAD work by the end of the year. Once that is complete, we will start using the CAD info to begin making parts for our airplane. From this point on, when we make a part for our airplane, we will be doing it using the same processes that we will use in production later.

That's it for this update. Thanks for stopping by.

Another Prowler Completes 1st Flight!!!!

2010-08-03T14:06:00.000-07:00

Congratulations to Bud Tedesco on completing his 1st flight! Bud reports that he and Prolwer N12BT took to the skies on 30Jul2010. Bud says the plane flies great and is very light and responsive on the controls.

Here is a video of Bud starting his Prowler before the first flight.

This is the video of his first flight. Right after the initial lift off you will see the airplane appear to sink back toward the runway. According to Bud that was intentional as he was going to set the airplane back onto the runway because of a "funny" engine sound. But the Prowler moves so fast that he realized that he was out of runway, so he again powered up and pulled back on the stick to continue the first flight. That sink apparently caused a few gasps back with the ground crew. He didn't really mean to scare anyone, and there wasn't anything really wrong with the plane.

Here are the YouTube links for these videos. You may find these have a little better quality:

http://www.youtube.com/watch?v=ZB1Ce1esYVc
http://www.youtube.com/watch?v=yJJrCm1tLec

Bud's gripe list from the first flight includes:
1. Oil pressure - seemed to be be fine before flight @ 65psi, but he noticed it was around 15psi during the flight.
2. A heavy left wing - will most probably be fixed with some simple rigging changes to ailerons and flaps.
3. Engine running rich - Bud is going to dig into the books and see if he can adjust the mixture linkage and mechanical fuel injection system to get a better setup.

He also reported that the flight controls are very responsive and you don't have to actually "move" the flight control to get the desired outcome - just a simple "pressure" will do.

Once again, Congratulations Bud!!! This is a monumental accomplishment. You should be very satisfied. Great Job.

I'm also WAY overdue for a Prowler Blog update. I'm going to try to get to that ASAP. Until then I'll be working the day job and dreaming about our first flight. Thanks for stopping by.

We Had Pop In The Shop Again!

2010-04-23T11:50:00.000-07:00

It's hard to believe it's been 3 months since my last update! The end of March signaled the annual spring trip where Grandma & Grandpa stop to see the grandkids on the trip home from snowbirding in the southwest. It's great, because Prowler gets the benefit of having a retired Iron Worker in the shop that has spent an entire winter in an RV without welders, grinders and cutting torches. We got a lot done - but I think he thought he was a job foreman again! Here's the list of topics in this update:
1. Sheet Metal Brake Update
2. Grinder Bench Fabrication
3. Plasma Torch Mods and Update
4. CAD work
5. Bryan's TW Strut
6. Forks for the Tractor
7. 30" Shear/Brake/Sliproll Fix
8. Next Update

The balance of the time since the last update has gone into working the day job and hasn't allowed a lot of time in the shop. On with the update:

1. Sheet Metal Brake Update - By far, the majority of the shop work in the past months has been working on the 8’ sheet metal brake. Here’s what it looked like after the restoration of what we initially got.
After completing this restoration of the existing parts, work began on the new parts that would be needed to build the missing top clamp. Using ideas from pictures of this same brake found on the internet and combining those with ideas from other existing designs (and a few of our own ideas), we came up with a plan. These are a few of the parts that were designed and machined to create an eccentric system that when rotated (by a handle) will create the lifting force to lift the top clamp (so the material can be slid into the brake).

Here are those same parts cleaned up and installed on the brake. When the round part facing outward is turned, the bolt is lifted upward (because it is off center). The other end of that bolt is welded to the upper clamp of the brake. Below you can see where the handle was welded onto this eccentric plate.

Here’s a pic of the long top clamp pieces being installed onto the end plates. There is a piece of a steel beam (upside down “T”) that you can see one side of in this picture. That beam was cut lengthwise by our Prowler Plasma system. That piece of upside down “T” iron is what the rest of the upper clamp assembly was built around.

Here are a few pix of the almost completed brake. It still needs to have some “tweaking” done and also needs painting. Notice the stiff-backs that were added to the upper clamp assembly and the counter-weights that were fabricated for the folding leaf (to assist in bending the material). These were all missing when we got the base unit.

2. Grinder Bench Fab – As mentioned in an earlier post, we got this carbide grinder setup for free (for getting the sheet metal brake out of the gent’s backyard). The internal motor had burned out, but someone had modified it and set it up to be used with an external motor. The cabinet that it was mounted in when we got it was trash, so we pulled out the good parts and installed them into a new bench. There will eventually be several other bench grinders and buffers installed onto this bench so that all of these tools will be organized into a single, movable work station.

3. Plasma Torch Mods and Update – Because we built a new torch height control system for our plasma setup, the distance that the torch head actually stands off from the gantry and carriage had increased by about 5 inches. You can see the amount of stand-off in this pic.

That caused a problem with trying to cut long pieces in between the structure of the plasma table. Even though there was 8’-4” of space between the frames of the table, the torch could not travel far enough to the left to use all of this space in between the structure of the table. So, we had to extend one of the rails that the gantry runs on. It really amounted to cutting about 6 inches of this rail system off of one end of the table and mounting on the other end. Then moving the X axis gear track to the left the same distance. In this pic you can see this new extension piece after it was cut off the right end of the table and added to the left side of the table (and the gear track moved).

The problem is now solved and we are able to cut in lengths up to 8’-2”. As mentioned above in this post, we used the plasma torch to make one of the parts for the sheet metal brake. We cut an “I” beam in half the long way to make a “T” shaped part. The torch worked great and the part came out nice and straight.

Overall, the plasma setup is working really well. It’s also becoming more useful as we learn more about how to use it. We’ve gone from using 60A tips to using 40A fine cut tips and they work very well. So far we’ve only cut steel, but we’re going to expand into cutting aluminum sometime soon. Recently while cutting some parts for a friend, the auto height control system was proven to be working just as it should. It tracked around a long part maintaining a perfect cut height even though the material was warped over ½” from end to end.

Also, as we get better at processing CAD drawings into machine code (G-code) we are finding it quicker to make parts with the plasma setup than any other way. Hopefully this tool will turn out to be a great way to cut a lot of our parts. Speaking of CAD work:

4. CAD Work - Hundreds of hours are going into creating these CAD drawings of each part of the aircraft. Turns out that the easiest parts to draw are the ones with straight sides, angles, circles etc. that can be re-drawn from scratch. The parts we're currently working on are very tedious and time consuming. This is because they have curves that cannot be replicated in BobCAD. So the parts must be traced, scanned (with a large format scanner @ Kinko's) and then the scan imported into BobCAD. However, when the drawing is vectorized in BobCAD it does not become a clean, usable drawing. It's takes hours of cleaning up and detailing the drawing to get the shapes correct. Here's a screenshot of a recent part (center wing section middle rib#4):

Here's a close-up 3D view:

5. Bryan's TW Strut – One of the fun things we got done during this update period was completing Byan's TW strut. It was a very good project for us to learn "the ropes" on getting real machine work done. Overall, the project turned out great. Here's a couple pix of Bryan's Completed TW Strut.

Here's a couple of pix where he has it partially installed for testing the fit, etc.

Bryan said he was going to give us an A+ with extra credit, but we only ended up with an A+ because we had one bore that was just a smidge too tight and he had to file it out just a bit to get the bolt to go in. The new bore dimension is now noted on the drawing! Glad you liked it Bryan.

6. Forks for the Tractor – This project was not even on the agenda, but a set of forklift forks (with the rack for the forks) came onto Craigslist at a good price. We’ve wanted to have forks for the tractor, so we purchased them. It only took a little modification (and extension) to make them fit onto the tractor using the same pin points that are used to attach the bucket.

It works great! It will be very nice having the ability to lift shipments of 2024-T3 off of the delivery truck (someday).

7. 30" Shear/Brake/Sliproll Fix – In a previous post we showed this combination tool that we got at a great price. We’ll, the broken arm has been repaired and the unit now works fine. It still has to get mounted to a movable table or bench – but it’s now ready to work.

8. Next Update: In the next update we'll try to have a status update for each of the current builders. Bud should be close to his test flight. Chuck should be flying off his 40 hours. Ray has been testing hydraulics and electronics and is headed towards mounting his engine.

This update comes to you in the midst of the best landscaping time of the year in northern CA. Since we haven't had a green lawn in 5 years, the pressure is on (me) to get the landscaping and irrigation done @ the Prowler (West) homestead - before the ground dries out and gets so hard you can't drive a nail into it. So, there won't be a lot of shop work getting done for a while. However, the CAD work is portable and the day job provides time sitting in a hotel to work on that.

That's all for this update. Thanks for stopping by to keep an eye on us.

2010 Is Off To A Great Start

2010-01-31T10:14:00.000-08:00

Welcome Back. Happy New Year, and thanks for stopping back to check in on us at Prowler Aviation. We are off to a really good start in 2010. Here are the bullets for this update:
1. CNC Jigs
2. Tailwheel Strut Fabrication
3. Airplane CAD Work
4. A Free 8 Foot Sheetmetal Brake
5. More Tools
6. Cabi Saves Kit #9 from the recycling SCRAP HEAP!!!
7. Bud's Airplane (Kit #16) Attempted First Engine Start
8. Chuck's Airplane (Kit #12) FLIES AGAIN
9. Ray's Airplane (Kit #10)

Here's the Latest:

1. CNC Jigs - We recently had to fabricate jigs for 2 parts that we have in the CNC process. To make production as simple, pratical, and repeatable as possible you have to find a way to hold the stock rigidly while the machine does it's thing. You also have to find a way to hold the stock without machine hitting something that it's not supposed to. So far we made jigs for the steel wing plates and the TW strut.

2. Tailwheel Strut Fabrication - is nearly complete. Bryan has asked to have a TW strut fabricated. His kit never had one and he's going to begin the fuselage soon and wanted to start lining up all the parts. So, as we've shown in previous posts, we did the CAD work for the TW strut and got the machining done. One of the steps in the process was CNC shown above (jigs). The bushing holes still need to be reamed and the bushing pressed into them - but the processes are now in place to make these parts in the future.

3. Airplane CAD Work - We've been working diligently on the CAD work for the airplane. We've finished the drawings for the Vert Stab, Horz Stab, Rudder, Elevator, Main Wing Spar, Outboard Wing Spars, Rear Spars, Torque Boxes. The measurements have been done for all of the Center Wing Framing Components and the Outboard Wing Framing Components. When the drawings are completed for these last two sections, we will have completed a CAD drawing for roughly 1/2 the airframe components. The next step in process will be to go back and assemble the individual components into sub-assemblies where appropriate.

4. A Free 8 Foot Sheetmetal Brake (Sort-of) - We got a line on an 8 foot sheetmetal brake that a gent in SoCal was giving away to a good home. It's not a complete sheetmetal brake, however, and needs a lot of TLC. The base of the brake and the bending fence are are what we've gotten, but it's missing the top parts that clamp the material while bending. With a bit of elbow grease and fabrication of some parts, it will become a servicable unit - for a lot less than purchasing one. So far we've taken possesion of the brake, transported it to the shop, taken it completely apart, stripped and sand-blasted all of the parts and then painted everything. The next time in the shop we'll get pieces all re-assembled and get a start of fabricating parts to build the top, clamping part of the brake. Here are pics of what it looked like on arrival:
Started the tear apart, cleaning, sandblasting and fixing:
Sandblasting (effective but VERY tedious and messy!): Painted Pieces ready to go back together:

5. More Tools - We ended up picking up a few more tools from the gent that gave us the sheet metal brake. One of the tools is a Tooling Cutter/Grinder. It's a machine to make precise angles to make and/or sharpen toolings for mills, lathes, etc. It was a good deal and it will be nice to have the capability. Here's a pic: Clean up and restoration of this tool is on the back burner for now. At least until we need to sharpen some tooling.

The other item we got was a 30" combination shear, press brake and sliproll. Here it is before cleaning: It was a great deal because it has one broken arm. Here it is after cleaning:Here's the CAD drawing for the Prowler Plasma to cut out a new arm. We should have it fixed up in no time. More later. One of the great things of building this company slowly is that we have the time to find these "diamonds in the rough" and polish them up. It saves a lot of $$$ - but it does take time. Since we are not in any huge hurry, we can use this process to position the company for financial soundness.

6. Cabi Saves Kit #9 from the recycling SCRAP HEAP!!! - Late last year Cabi completed tracking down the old Prowler Aviation's Kit#9. The kit had changed hands a few times after it had been purchased from George. Somehow Cabi tracked it to a local college that it had been donated to. It languished there for years and ended up stored in an old CONEX box container. The college was very close to selling it for the scrap aluminum value. Cabi got the kit for value of the scrap metal. What a deal! Nice work John. Here are some pix:

7. Bud's Airplane (Kit #16) Attempted First Engine Start - Got an email from Bud recently and he reported that he's attempted the first run-ups of his airplane. The engine didn't fire and after some investigation he found out that many of the silver solder joints on the fuel injection manifold had somehow become (essentially) closed off. So, he is in the process of making this right and we expect to hear good news from him soon. Here's a file pic of Bud's airplane from a visit last fall.

8. Chuck's Airplane (Kit #12) FLIES AGAIN - Last year Chuck was having engine troubles. The engine wasn't running real well, there were engine oil and water cooling issues - among other things. Chuck found a sharp fellow to help him tear the engine apart and find out what was going on. What they found was that one of the distributors was damaged and the engine appeared to be running in a severly "advanced" ignition timing condtion. This had badly damaged one pistion and somewhat damaged others. After many months of rebuilding, the airplane flew again in Jan. Chuck reports that the airplane flew well, the gear cycled well but the engine was not producing "linear" power. The engine ran great and "pulled like hell" at takeoff power, but as soon and the power was reduced, the engine power got "mushy" and difficult to control. He and his technician decided that there were some tuning issues between the mechanical fuel injection system, the supercharger system and the engine. They decided to remove the supercharger system from the airplane. After that, the engine ran great, the power was very controllable, and the airplane performed very, very well. Here's a pic of Chuck and his plane from a builder visit in 2008. In a later flight, the test pilot reported that the only remaining "gripe" was that at about 175 mph he ran out of elevator trim. So they will be focusing on getting the Horz Stab incidence set correctly in the near future. After that, Chuck says he will pay his pilot to fly off the 40 hours required to get the Experimental Certificate and then he will be putting the airplane up for sale. Stand by for more.

9. Ray's Airplane (Kit #10) - Is almost ready to get an engine - Ray reports being very close to completing the avionics installations in his airplane. He wants to get most of the wiring completed and get the avionics mostly complete before moving on to the engine and firewall forward. His goal is to get a good start on the engine mount and the the engine installed this year. Here is the most current pic we have of his instrument panel.
That's all for this update. More when additional info and time will allow. Thanks for stopping by.

Happy Holidays From Prowler!

2009-12-24T08:46:00.000-08:00

Hello again and welcome back again for the last post of 2009.

Well, this post is dedicated to only one thing - the Prowler CNC Plasma system. The past 2 weeks has been one last, large effort to get this system up and running and we're happy to report that it is - FINALLY!

Here's the report:

The first step in the last big push to get the system running was to get our shop compressed air up to par. Plasma torches use a fair amount of air and it needs to be clean and DRY! The old compressor didn't have the capacity to keep up the the almost 8 CFM of air required to of the PowerMax 1000 torch. A friend recently upgraded to a new larger compressor and we purchased his gently used unit. This machine stores 80 GAL of air and can provide 17.5 SCFM continuously @90PSI. More than enough to supply the current Prowler Shop. Once the unit was in position we needed to install a new regulator and plumbing to get the air directly to the torch in the most direct means possible. Here is the new piping and the tie-in to the existing manifold: Once we got the air over to the torch area, we finished the hook-ups to the refrigerated air dryer mentioned in the previous posts. The dry, clean air is critical to getting good cut quality. Here are shots of the torch cart (with the air dryer and computer card hook ups incorporated). The pic above also shows the new (used) computer we had to purchase for the CNC system. The previous computer was still having a problem running the control software (Mach3) and locking up the computer frequently. So we ordered a refurbished 3 Ghz P4 machine and loaded all the software onto it. We haven't had a problem running Mach3 since. With all that in place we were ready to start doing test cuts. Here is the first test cut: As you can see, it's not good. Lots of dross, very angular cuts, just a poor quality cut. After a while we got the cuts to improve a little, but they were still not good cuts. After several calls to Hypertherm and CandCNC we made a few tweaks and got the cuts to get a little better. But they still were not good. Something was still not right. At one point, a newly installed nozzle was blown off in 10 seconds of turning the torch on. Here are some pix of the carnage happening to the torch tips. This is not normal wear. Hypertherm recommended taking the PM1000 in for service. After removing the torch from the table and packing it down to the local welding shop the technician there noticed a few things about the modifications made to the hand torch that didn't seem right. He was right about one thing, and that made us go back and review the whole modification. Turns out that the biggest issue was that by mounting the brass "guts" of the hand torch in the aluminum wand (shown below); the nozzles were ultimately getting grounded through the table and essentially shorting out the torch. A few well placed rubber insulators got everything set right and we were able to start making good cuts. The part below is for the same friend that the air compressor came from. They are hooks to weld to the top of a tractor bucket. They're used for hooking up chains, straps, etc. for lifting or pulling. In any event, the torch is now able to cut 1/2" thick steel with pretty good cut quality. Our system does leave a small amount of angularity to the cuts on the 1/2" steel, but according to Tom of CandCNC, 1/2" steel is at the limit of the capability of a PM1000. If we wanted to get nice square cuts on this type material we'd have to upgrade to a much larger torch. But, since the thickest material we need to cut for the airplane is barely 1/4" - this system should work great for us. Here is a pic of the whole Prowler CNC plasma system: From here we must expand our plasma cutting knowledge to include using different types of nozzles, the 40Amp fine cut nozzles in particular. Also, we have to learn to cut some different types of materials for the airplane; mostly Chromoly Steel and Aluminum. We'll report on that in the New Year. We also have some interesting info for the next post on a long, lost kit that was saved from the scrap heap! Stop back again next year.

Merry Christmas and Happy New Year from us here at Prowler Aviation.

A Little Slower - But Still Working

2009-11-29T10:00:00.000-08:00

Welcome Back. We hope everyone enjoyed a Happy Thanksgiving this year. It's been a little bit slower paced around here lately, but we've still been working.
In this update:

1. Sheet Metal Brake Shoe
2. CAD Modeling
3. New Rotary Phase Converter Motor Stand
4. Plasma Torch Air
5. The Great Wall of Prowler

1. Sheet Metal Brake Shoe - In preparation to start bending a lot of sheet metal, we needed to modify our sheet metal brake to bend our aluminum with a radius. Standard sheet metal brakes come with fingers or shoes that will bend very sharp corners. Aluminum cannot be bent that sharply or it will crack between the metal grains. Most bends for Prowler Parts need 1/8" radius bends. So we needed to put the Bridgeport to use and make a shoe with a 1/8th" radius.

Now making hundreds of radius bends will be fast and easy with the modified brake. Should help speed up production. This covers the parts up to 4 feet. We've got another solution for parts over that length. Here's what the test piece looked like.

2. CAD Modeling - We've been using our CAD software to begin systematically modeling all of the parts and patterns for the Prowler. We learned to use the software while modeling a few of the parts (e.g. Tailwheel Strut) we've already mentioned in previous blog posts. But now we've begun to model all the parts in ernest. In the past two weeks we've completed the modeling of all the Vertical Stabilizer parts and the Horizontal Stabilizer parts. We're now starting on the parts for the center section of the main wing spar. BobCAD-CAM Ver. 23 was well worth the cost. Here's a sample of the software while modeling the Horz. Stab. skin.

3. New Rotary Phase Converter Motor Stand - While spending hours machining out the radius-ed shoe for the sheet metal brake, it became apparent that having the motor of the rotary phase converter mounted to a shelf on the wall behind the mill was not the best solution. The motor vibration was transmitted into the wall and amplified by the wall resonance. So, we used another of our new shop tools (MIG welder) to weld up a new motor stand that mounts to the concrete floor. It turned out great and the motor noise is substantially reduced.

4. Plasma Torch Air - We really need to get the plasma torch going. We're getting to the point where we really need to start cutting a lot of parts and we want to be able to use the plasma setup to do this - just like we will eventually be doing for production. We recently installed a new computer and the system is essentially set-up and tested. Here's a movie of the system cutting out a sample part we created (without the torch on):

The torch has tested fine as well, however, the weak link in the system is compressed air. Our air compressor did not have the capacity to keep up with the air required for the torch. In addition, the air cleaning/drying system we set up previously was not going to be adequate.

To solve the air supply problem we purchased a new (used) air compressor. Plans are in progress to find an acceptable to place to set up the air compressor outside of the shop. This will keep the noise down and make more room inside the shop. It will, unfortunately, require plumbing electrical out to the compressor and plumbing the air into the current manifold set up we have. Should be couple day project. More to follow.

To dry the air we purchased a new refrigerated air dryer and the torch cart has been modified to hold it. We still have to plumb the filter and the misc hookups. This project will be at the top of the list in the coming weeks.

5. The Great Wall of Prowler - Since the Prowler (West) shop was built we've been wanting to widen the driveway around the shop and add room to get in-and-out of the south garage door. We recently got access to a lot of broken concrete and fill from a job site. We transported it all to the shop and have begun to build a retaining wall around the front of the shop. It will give a lot more space for driveway and should help improve the look of the property. Unfortunately not everything can be directly related to building Prowlers!

That's it for this update. We'll update again when there is more to report. Thanks for stopping by.

IT'S BEEN A BUSY MONTH!

2009-10-01T08:20:00.000-07:00

Hello Again - It's been really busy this past month around the Prowler Shop. Included in this update:
1. Kit #13 Has a New Owner
2. Builder Visit w/ Bud Tedesco (Kit #16)
3. Redding Air Show
4. Bryan (Kit #007) Progress
5. Work on Tailwheel Struts
6. First Attempt At Bend Radius Jig
7. Added DRO to Bridgeport Mill Quill
8. Installed 3 Jaw Chuck on Lathe
9. Purchased a MIG welder

Overall, we're continuing to make progress on our first aircraft and Prowler the company. There is much to do to structure what we do now to make it repeatable in the future. Generally, when we work on the airplane we don't get much done on the company. And, when we work on the company, we don't get a lot done on the actual aircraft. But, all in due time. On with the update.

1. Kit #13 Has a New Owner - You may remember from our JAN09 post that Rick in Memphis purchased the RW&B aircraft (Kit #001) and also Kit #013 from the former owner in JAX. After reviewing and inventorying all of the parts, Rick decided to put Kit #013 up for sale. The kit was recently purchased by Roy Farris of Franklin, IN. Roy should take custody of the kit within the next few weeks. We'll pass along any new information once Roy gets his kit. Here's a couple of pix of Kit #013 taken when Rick was purchasing it earlier.

Congratulations Roy! We look forward to working with you in getting your airplane together and flying. Please send us your pix and your thoughts that we can share with everyone.

2. Builder Visit w/ Bud Tedesco (Kit #16) - On a recent trip to MCO for recurrent training, I was able to get up to Mount Dora, FL and visit Bud and see his aircraft. He's doing a fabulous job on it and is hoping to have it flying by the end of the year! Nearly all the systems have been installed and tested. He is currently working on installing all of the fairings and finishing up odds-n-ends. Here are a few pix of Bud's Beauty:

So far, Bud is the only builder that has incorporated a sliding canopy design into his Prowler. He came up with an ingenious design that allows it to work on a cockpit that is wider at the front than at the back. We'll look at incorporating this into our aircraft. BTW - that's Bud waving from the cockpit in the first picture above. Great job Bud - we'll keep tracking your progress. Hope you make your goal to have your aircraft fly this year.

3. Redding Air Show - The promoters of the Redding Air Show called George this year and asked him if he would, again, display his Prowler at the air show. He agreed and we spent Thurs before the airshow getting Kit #005 out of storage, towing it up to KRDD, putting the wings on, and giving it a much needed bath. This was our first opportunity to see how the airplane is taken on and off of the trailer, how the wings are put on and taken off, and enjoy seeing folks enjoy the airplane. There is now doubt about it - this airplane gets lots and lots of looks!
We may have gotten even more looks if it hadn't been 112F on the field that Saturday! It was hot, but it was a great show. Of Course, these guys always get the most looks!

4. Bryan's (Kit #007) Progress - A bit of a slowdown at work has allowed Bryan to really get some work done on his Prowler. He recently sent me a video of his flap operating system in operation. He chose an updated version of the electric linear actuator that George and others have used to operate the flaps. This design has a ball-screw drive with automatic clutching at each end. This negates the need for limit switches, provided that you get the correct stroke length. It does, however, require that a different mounting system be created to attach the fwd end of the actuator to the bulkhead. Here's a video:

http://www.blogger.com/video-play.mp4?contentId=76805bafaeb2cb07&type=video%2Fmp4

NOTE: Bryan also requested us to ask if there are any current builders out there that need the high tensile wing bolts - please contact us. He is going to order some of them and will order enough for everyone. These are sold only in lots of 10 (w/ certification paperwork). He will order enough to get everyone what they need and divide them up when received. Email us for details.

5. Work on Tailwheel Struts - We've ordered the stock material for the tailwheel struts and identified a machine shop to begin making these from our newly made drawings (see previous post). This is to support the current builders that are in need of these items. While we're at it, we'll make a couple extra struts - one for our aircraft and one for possible future needs. Here's an updated 3D version of the TW strut since we "tweaked" the design a little. We should have some new pix for the next update.

6. First Attempt At Bend Radius Jig - We made a first try at making a bending radius jig to make bending 2024-T3 in the box brake easier and faster to do. Since we have a lot of this type of forming to do now (and even more in the future) we are putting time into making these processes very quick and efficient so production can be as efficient as possible. So, we tried welding a 1/4" round stock to the edge of a 1/4" piece of flat bar to create a "jig" to lay on top of the material to bend in the brake. Unfortunately, the heat from the welding stitches caused the jig to warp and made it unusable. In addition, we found out the the top fingers on the brake cannot be adjusted back far enough to accommodate this design. So, we're on to "Plan B" and should have some more info and pix in the next update. If at first you don't succeed - try, try again.

7. Installed DRO on Bridgeport Mill Quill -
This project turned out much more successfully than the one mentioned above. For less than $40 (including shipping) we purchased one of these quill DRO's. It did not, however, come with the mounting hardware - so a little imagination and fabrication were in order. Here's what we came up with.We have one more idea to make this more practical and useful. More to follow.

8. Installed 3 Jaw Chuck on Lathe - Last year we purchased a older used lathe and restored it back to a usable condition. It came with a 4 inch 4 jaw chuck, but we need the convenience of a 3 jaw chuck so we purchased one from ENCO. Trouble was, this lathe is so old that no one makes a back plate for mounting the chuck (uses a 1-1/4" 12tpi fastener to thread onto the lathe spindle). So, we had to make one. First step is to weld a 1-1/4" 12 tpi nut to a piece of 1/2" plate that has a 1" hole cut through it.Next, put it on the lathe to true up the face and side. Also, cut a shoulder on the edge to give a raised area which will fit into a recess on the back of the chuck (ensures it is concentric when installed on back of chuck). Drill 3 holes to bolt the back plate onto the chuck: Install the back plate onto the chuck: Install the completed chuck and back plate onto the lathe.
The dial indicators says run-out is less than 0.003" from side to side (less than 0.0015" from center to OD of the chuck). Good to go! Eventually we'll get a bigger and better lathe and this will be converted and set up to make one or two specific parts. But for now, we can use it to make several of the aircraft parts as well as general shop work.

9. Purchased a MIG Welder-
To facilitate making many of the jigs, tooling and other items needed to produce Prowler parts we needed to purchase a MIG welder. After months of watching the local classified and craigslist we found the right package at a great price.It's already been put to good use and it welds great. Of course, all the weldments for the aircraft parts will all be TIG welded (which we will outsource to a qualified welder initally). However, eventually we hope to purchase a TIG welder and take welding courses to bring this part of production in house as well.

Those are the high points for this installment. Next post we'll have a more complete update on the status of all the builders and their aircraft. Thanks for checking in on us and look for a Halloween update.

A FEW MORE STEPS

2009-08-29T22:45:00.000-07:00

A FEW MORE STEPS

Just a quick post to update the latest Prowler progress:

1. Catch up on the Vert Stab.
2. Horiz Stab Work
3. Computer Modeling Parts
4. Builder Update

1. Catch up on the Vert Stab. – In the previous post I mentioned that Dave has been working on assembling the Vert Stab Subkit. Here are a few pix of his handi-work.

2. Horiz Stab Work - Dave's been itching to get to more assembling and I wanted to do something besides work on the plasma setup, so I decided to get some creative work going for a change and started fabricating the parts for the horiz stab subkit. These 8 parts were about 9 hours of work:

Now they have to be heat treated, since they are formed from 2024-O (soft) material. Here are the horiz stab spar parts and cover plates cut out and waiting to be bent up in the sheetmetal brake. I used a buddy's sheet metal shear and it made cutting these out very easy.
Other horiz stab parts:

3. Computer Modeling Parts - Well, we have begun in earnest to model all the parts that make up a Prowler. This will be needed to setup the CNC plasma torch system to cut the flat parts. We purchased copies of BobCAD-CAM and are in the learning to use it process (steep curve right now). It's actually a very powerful program for the price and fairly intuitive - once you watch several of the video tutorials. Here are some examples: The vert stab aft spar;
Main Landing Gear Pivot Link:
Tailwheel Strut:

Close up of the 3D view of the strut - BobCAD-CAM ver 23 does well with the 3D:

Now, only 687 more parts to go (just guessing)!

4. Builder Update - Ray Siem reports that Chuck has his airplane and engine back together and the engine is running well. His problems apparently stemmed from a damaged, or lack of, the mechanical stop in one of the distributors. On one of them the cap had a hole in it where it looks like part of the centrifugal stop system exited the scene and it let the engine vacuum advance run way to advanced. He reports that the engine is running well with coolant temps in range and no noticable issues. He is going to continue to test run the engine while he is going also going thru some medical issues. No date for the next test flight, but we'll keep ya posted.

That's it for this post. It's late and crew services could call in 4 hrs. Thanks for checking in.

SORRY - IT'S BEEN A WHILE

2009-08-22T17:51:00.000-07:00

Well, it’s been several months since the last post, but if was for good reason. During that time a lot was happening. In this update:

1. Prowler Territory (was) Under Siege

2. Vert Stab Build

3. CNC Plasma Success

4. AirVenture 2009

5. Horz. Stab Started

6. Repairs to Bridgeport and MLG Forks

7. Builder Updates

8. Event Horizon

1. Prowler Territory (was) Under Siege - On May 7th, Todd was notified that an agency call TANC (Transmission Agency of Northern California) was planning to build a 500 KV transmission line with 150 foot tall massive towers across 2/3 of his property.

The project was eventually abandoned in Jul. But, from May 7th until July 16th it consumed every minute of every day that he wasn’t making a paycheck helping to form and work on a grassroots opposition to TANC (with over 400 other Northern California residents affected by the same project). In all, the project was proposed to be over 600 miles long and affect some 7,000 land owners. On July 7th the Sacramento Municipal Utility District withdrew from the project and took $0.5B with it. Within a week all the players pulled out of the project and all landowners got their properties back. Good riddance.

2. Vert Stab Build – During the time that Todd was fighting TANC, Dave was working on the Vert Stab subkit and creating the associated portion of the Prowler Assembly manual. Using the old version of the assembly manual, Dave completed most of the vertical stabilizer including priming of the parts. The final assembly has not yet been completed because we are looking into re-doing the rudder hinging system. Once we complete this re-design the remainder of the vert stab will be assembled. Sorry, couldn't find any pix this time, we'll post them in the next update.

In conjunction with building our subkits, we have always planned to do a complete re-write of the entire Prowler assembly manual including new text, pictures, drawings, graphics and, if need be, video of assembly. Dave has made some very impressive changes to the manual while working on the vert stab and our future customers will, no doubt, find this new format much more readable and easier to understand. Nice job Dave.

3. CNC Plasma Success – After over 8 weeks of not getting into the shop at all, Todd was able to get back to work on Prowler business. Some of the recent accomplishments include: Completed troubleshooting computer & software issues with the system that runs the CNC plasma table; Completed more modifications to the CNC plasma table; Learned how to CAD parts using BobCAD-CAM ver. 23 (great program) and then CAM the parts using SheetCAM; and most recently – did a complete dry run (with torch off) of a sample part in the CNC plasma system.
If all goes as planned, we should be able to begin using the Prowler Plaz system to proof the concept and start making our parts for our airplane. The idea is that once we complete our company aircraft using this process, we will have the ability to use this for limited production of Prowler sub-kits.

4. AirVenture 2009 - This week, Todd, Dave & Bryan attended Airventure at KOSH. As always, AirVenture was busy and impressive. The A380 as HUGE, the WK2 was interesting, the warbirds were awesome and the airshows were great. Bryan was able to make it for 3 days, Todd and Dave were around for most of the week. We didn't, and probably won't, have a vendor spot at AirVenture for some time. Since we don't yet have anything to sell, we're keeping a low profile.

5. Horz. Stab Started - Todd got a little time in the shop last week and started to fabricate the horizontal stab. We hope to have the sub-kit built and shipped off to Dave for assembly in the next few weeks. Finding somewhere to cost effectively heat treat the few small parts in the horz stab that were formed from 2024-O might be the hold up. More to follow.

6. Completed repairs to the power feed system on the Bridgeport Mill - George came out recently and had some left over stock that he had cut up to make the MLG yokes (forks). We start to use the mill and determined that the power feed was not working correctly. After some investigation it turned out to be a loose bushing deep inside the mill head. So, we had to pull the head, remove the set screws holding the bushing, re-drill the centering hole, re-install the set screws, re-install the mill head, tram the head to square it to the table and (several hours later) bored out one of the strut holes in one of the forks.
7. Builder Updates - We have updates this time from Ray, Chuck, and Bryan.

Ray - has been making really good (and impressive - as always) progress on his plane. He's currently focusing on the instrument panel and electrical wiring. He's planned out an impressive panel with all the bells and whistles. He has incorporated Dynon Avionics with full autopilot, an airliner quality gear operating system, and beautiful landing lights (see a previous post).

Chuck - has had to tear down his engine. Turns out there was an issue with the vacuum advance system in the ingition. There was no limit for the advance system and the engine was damaged. During the teardown Ray stopped by to get some pix of the PSRU and engine. The engine was almost back together when Ray was there and Chuck is planning to run the engine again soon.

Bryan - is mostly done with the wing and is beginning to lay out the cockpit floor in preparation for building the fuselage onto the center section of the airplane. He is also working on finishing the MLG doors and wheel wells. Bryan has decided to forgo the inner gear doors and his plane with have 737 style wheel wells.

8. Event Horizon - What we have coming up on the event horizon:

Prowler CAD work - We are beginning in earnest to start modeling all of the parts needed to build a Prowler. This will happen over time, as we will go back and model the parts that we’ve already made via other means and then move on to modeling the parts for the work we are currently doing. Again, the idea is that by doing this, we will eventually end up with the entire aircraft modeled in a CAD format when we finish our company aircraft.

Prowler Plaz Testing – With the completion of a perfect test run of the Prowler Plaz system, now the real learning curve begins. We must do a series of test cuts to determine the ideal parameters to use for getting the best cuts on each type and thickness of material to be cut. These parameters include things like the best tips to use, the current setting, the optimal pierce height and cut height (controlled by voltage) and feedrate (cut speed). These parameters go into a library contained in the cutting system program that can then be recalled very quickly anytime a similar material is cut. But, the initial testing will take time to build that library. In addition, the plaz system needs a bigger air compressor to be installed and we are going to install a refrigerated air dryer to get the best cuts possible.

Main Wing Spar - The goal at Prowler West is to get the entire main wing spar fabricated, prepped and put into the wing jig by the end of the year. This effort is in direct competition with the above items for time - so some compromise will need to be made, but that's the goal.

Prowler Plasma Makes Fire!

2009-05-02T19:29:00.000-07:00

Hello again. Thanks for checking back in on us. In this update we tell you about:
1. A builder visit to Steven Rogers
2. Chuck's airplane had a second round of test flights
3. Prowler Kit #11 Lands in France
4. A quick trip to Sun-n-Fun
5. Prowler Plasma system finally makes FIRE!

1. Builder Visit to Seattle
Todd had a long stay in Seattle recently and had an opportunity to get together with Steven Rogers and his aircraft. His aircraft was build from George's kit #14 by him, his father, and (on several occasions) George too. It was a great visit and we learned a lot about the airplane from Steve's experiences so far in his initial flying and testing. Unfortunately, he recently had a hydraulic issue and the tailwheel collapsed while taxiing and landed on the rudder. So Steve is in the process of making the necessary repairs and we'll have more pictures of the airplane from a follow-on visit. Steve's airplane was the 4th Prowler that we know of to fly and wish him well getting his repairs done soon so that he can start to enjoy his bird instead of work on it. Here is one picture of a mod that Steve did to his Prowler that has dramatically helped to improve airflow through the engine compartment. Thanks for the Visit Steve.

2. Chuck's 2nd Round of Test Flight
We got news of Chuck Westcott's second round of test flights via Ray Siem. The flight's were successful, however, Chuck still reports having water cooling problems. He is in the process investigating the problem and we'll try to have more details in the next update.

3. Prowler Kit #11 Lands in France.
Nicolas Hombreux reports that the shipper has delivered his kit. He has begun un-crating, inventorying and organizing his parts. Here are a few pix: He promises to have more pix of him with the kit for the next update. Congratulations Nicolas! We look forward to helping you get your airplane built in the years to come.

4. Sun-n-Fun
A recent pop-up trip allowed Todd and Dave to get together for a quick Prowler Shareholder's meeting at Sun-n-Fun. Dave flew his certified aircraft into LAL for the annual get-together and we got to spend some time checking out potential suppliers and vendors. We are fairly interested in a FWF package that is being offered by Geared Drives out of Conroe, TX. Bud Warren has designed a very nice self contained PSRU that is designed to work with any SBC engine, is very solid and is virtually plug-n-play. He is marketing a FWF package for the RV-10 buyers that we think is very strong. Check it out here: Geared Drives We are giving this some strong consideration for the Prowler - if we can make it fit. Time will tell.

5. Prowler Plasma Makes Fire!
After months of research, lots of money and lot of modifications the Prowler Plasma system finally fired for the first time. The latest accomplishments include: troubleshooting the installation of Mach3 into the computer; unlocking the secrets of remotely triggering the Powermax1000; and learning the correct order in which the consumables are attached to the machine torch. With all that done - the machine finally moved and fired under it's own power and we are pleased with the results. Most recently we "tuned" the motors and checked the system for accuracy on each of the X, Y & Z axes. With just a little tweaking the X axis moved exactly 80 inches when we told Mach3 to move the X axis 80 inches. Should be good for making spar caps and other long pieces.

Now the real learning starts. Figuring out all the software that will eventually allow us to make parts with the plasma setup. It looks like we will be designing (modeling - actually) our parts using the new BobCAD-CAM-ART version 23. Then those files will be fed into SheetCAM TNG to create the actual tool paths and make the G-code to prepare the file for the plasma setup. Then those get sent into Mach3 which will actually cut out the parts. Easy right?!?! That's 4 major, new, unfamiliar pieces of software to learn if you include G-code itself. Despite that we've figure out a few things already. Here's a line drawing made from a "vectorized" copy of our "raster" style Prowler Logo: And this is the first Prowler Sample Part - it's nothing really. Just something made up to learn how to use BobCAD, SheetCAM and see if we can get it to move the table with Mach3: We will find out if the machine moves correctly the next time we're in the shop. More later.
That's all for this update. We'll post again in a few weeks. Thanks for stopping by.

More Production Capability Progess

2009-04-08T16:04:00.000-07:00

Thanks for stopping in to check on our progress. Well, this is a BIG update - but the BIG boss was in town lately, and we got a lot done. Todd's parents recently made their annual spring visit to see the grand kids and Prowler also enjoyed some big gains from "Grandpa's" visit. As a retired Ironworker, Dad helped get several tools running, tuned up, and generally "shape the place up a little."

In this update:
1. Hydraulic Press
2. Bridgeport Mill
3. CNC Plasma Table
4. Builder Reports

Before we get started, just a few thoughts on where Prowler Aviation is today and where we hope to go in the future. In this update we will cover several facets of building our capability to manufacture parts for constructing our first Prowler. Our plan is to develop and use these processes to make most of the parts for our first company aircraft. By going through the aircraft one subkit at a time, we will eventually have the capability to produce most of the airframe.
Once that is complete, we will have the knowledge necessary to make the aircraft in (at least) one manner. From there we will be able to consider larger scale production and how we want to accomplish that. There will be many options and we will consider as many as possible to come up with a practical, economical, scalable and reliable way to produce airframes.

We plan to put one of George's engine designs onto our aircraft, but we currently do not plan to offer the engine for sale with the kit. We've decided to limit our scope (at least initially) to producing the airframe and save the firewall forward for later. We will also have (for the first time ever) complete, accurate and thorough documentation of the aircraft. This documentation will include a shop manual (how to build each subkit), the builder's manual system (how to assemble the subkits into an aircraft), a complete parts list spreadsheet, a virtual computer model of the Prowler, and a business plan.

That's the long term plan. If you've been keeping tabs on us in this blog, you'll see that we've made significant progress on several of these areas. Most of this update will discuss progress on the manufacturing of parts. Last summer we completed the "big sort" and did much of the parts list work. Modeling of the airplane's parts will happen as we make the parts for our airplane. The CNC plasma system is almost ready - as you'll see later in the update. The builders manual system will also be accomplished as we build the airplane, subkit by subkit. Two of the subkits shop manual parts have been completed and the rest will be done as the plane progresses. The business plan will be the last task to be accomplished.

Our airplane currently has most of the wing spar parts (center and outboard) made. The spar is currently waiting on the cutting of a few parts with the CNC plasma system. We have the vert stab subkit built. The current goal is to make up the horizontal stab subkit, get the needed wing spar parts made, get the wing spar installed to the wing jig and press out the wing ribs by the end of the year.

So, there it is. We hope this helps to outline where we are here at Prowler Aviation. On to the update.

1. Hydraulic Press - To reach the goal of getting wing ribs pressed out by fall - a press would be helpful. So, this past two weeks we fabricated the hydraulic pump unit and installed it onto the press. The hydraulic ram had been refurb'ed previously and the pump unit was hooked up to it. We added a 40 amp 220volt circuit and a motor controller and presto - hydraulic press. Here's the pic:
The hydraulic pump is only good for 1500psi. However, the piston in the ram is 5 inches in diameter and that gives an area of approximately 19.6 square inches. This gives almost 30,000 lbs of pressure from the ram. Spread that force out over an average part area of 300 square inches and it figures out to about 100psi. Should be more than sufficient to fold up some 0.040" type O aluminum. Next comes the learning curve associated with actually pressing out parts. In particular, keeping the male and female dies lined up with the flat blank that will become the part as the press does its thing. More to follow.

2. Bridgeport Mill - It took a while to get the mill cleaned up and order some parts needed to fix up the mill a bit. The most interesting was replacing some head bolts. One was broken and one was beat up a bit. The change was fun: We got the mill moved into position, hooked up with 3 phase power and have even used it already to machine some slotted holes into some brackets for the CNC table. The 3 phase power comes from a rotary phase converter. We purchased a phase converter panel from Wyn Phase Converter and Supply (http://www.wnysupply.com/index.cfm) and scavenged a 3hp idler motor out of an old air handling unit from the local industrial surplus place. We had a little problem with the delivery of the phase converter panel. Apparently some components shook loose during shipping and managed to beat-up the rest of the components in the panel along the way. Here's what it looked like at delivery: Not wanting to wait the time that would be necessary to return it and wait for a new delivery, we set out to put the pieces back together. With the help of screws, glues and bailing wire we got it put back together and installed. It turned out well. Total cost for the phase converter was ~ $200. Here's a shot of the final rotary phase converter install: Here's the mill pretty much ready to go:
3. CNC Plasma Table - This project has been a long time in the works, but it will hopefully be the centerpiece in being able to practically and efficiently cut parts for the airplane. We've determined that upwards of 80-90% of the parts for the airframe are made from flat pieces of raw stock. After a bunch of research we decided to pursue this process as a means to make our parts. After more research we found that to use a plasma system to cut thin material requires a system that can automatically control the height of the torch. This provides the best cuts, maximizes the life of consumables and prevents wasting raw materials. To that end, we needed to make several modifications to our CNC table and torch systems to get the best chance of getting good parts. We've covered most of these in previous updates and are getting close to the big "first cut." The latest mod was to replace the signal generator (2-D box) that came with the Torchmate system with a new box (MP3000) that has 3-D control and auto torch height control. In fact, it's digital torch height control that is fully integrated with the X, Y, and Z motions axises.This box also, however, requires the use of a new software control system to control the table motion. You can check out the box details here: http://www.candcnc.com/ Look for Digital Torch Height Control. The software is Mach3 and it is an open source software that CandCNC has optimized for use with it's MP3000 system. You can check it out here: http://www.machsupport.com/.

Overall, the modification has been pretty straightforward. The hardest parts were actually installing the Mach3 software and getting it to run on the computer (various issues) and getting the new MP3000 box to interface with the Torchmate supplied motor controller box. We could have just bought new motors, controllers, power supply, etc. from CandCNC, but in an effort to get the lowest cost system possible, we wanted to use as much of the Torchmate system as possible. With enough research and help from CandCNC we were able to figure out the correct translation of wires to get the two boxes to work together. A quick re-wiring of the female DB-25 connector in the Torchmate motor controller box allowed the use of a simple 25 wire parallel computer cable to hook the boxes together. The box and software are installed and the table is working in all three axis's We also installed the digital torch height control system, but so far the test has been unsuccessful. Didn't have time to troubleshoot further before having to head off to the day job for the week. More to follow. We also made several "tweaks" to the CNC table to improve the accuracy. These included adding bracing, re-mounting the X axis motor and shafting, re-meshing the X axis rack and pinion gearing, and adding more Y axis cam followers to support the new floating torch holder. Here's the slotted bracket mods to the Y axis carriage plate for the cam followers to be added to. All these mods have greatly increased the rigidity of the CNC table which will ultimately lead to much more accurate parts. Unfortunately, we didn't get a pic of the overall CNC table with all the new mods. We'll post one next time.

4. Builder's Updates - A lot to report here too.
Kit #1 & Kit #13 - Rick has updated his Prowler site and moved it to a new web address. Check it out here: http://www.prowlerjaguar.com/
Kit #5 - Currently owned by George Morse. It is still for sale. You can see pix of this aircraft on Rick's site (above). We did an engine run-up recently and all is running well.
Kit #7 - Bryan's work continues.
Kit #10 - Ray has installed all the autopilot servos, gotten a new hydraulic accumulator, and cut his instrument panel and cut holes in his side panels for instruments. On the last visit, we dissected and spec'd out the propeller spinner and the radiators. Thanks Ray, nice work!
Kit #11 - Ben has opted out of the Prowler program. Cabi is brokering a deal to purchase Ben's kit and ship it to a new owner in France! In the next update we'll be introducing the new owner. The Prowler has gone global!
Kit #12 - Ray sent the following update on Chuck and his Prowler. In Ray's words: "Chuck flew first flight #2 this weekend. He said the plane handled well and the gear retraction went right. Chuck said the flight only got around the pattern once, the coolant temp went back up to 240 again, just like the last time, and the low oil qty light flickered. George said he didn't have any ideas about the coolant temp, but the oil might be low, and raise the quantity to 12 qts instead of 10 because there is a lot of oil trapped in the accessory case and almost as much in the prop and gear box." We are happy for your partial success Chuck!
Kit #13 - See Kit #1 above.
Kit #14 - We just found the following comments that Steve left after a recent blog update. Here it is in his words: " Hey Todd and company, Thanks for the news. I was able to test fly my airplane #14 late last November and I'm happy to report that my cooling issues are solved. 1.6 hour flight, no squawks.I cut a 4" by 5" square hole near the back lower corner of each of the small removable cowls that cover the exhaust pipes and covered them with stainless steel louvers. These allow air to exit the cowl, which draws air through the forward oil cooler, around the pan and out, and also allows the hot air coming out of the supercharger waste gate to exhaust overboard. The oil temp stabilized between 180 and 200 degrees, and was controllable with the cooler door on the aft cooler.I'm now just waiting for good weather in the pacific northwest to continue flight testing. More news to follow in early spring." Congrats and thanks for the update Steve.
Kit #16 - Bud has been working on tailwheel issues. We're planning a visit to meet him and see the plane later this summer. We'll update then.
Kit #17 - As mentioned above, Cabi has been brokering a deal with Ben's former kit. He also a some exciting news that we'll be able to tell you about in the next update.
Kit #18 - WYSIWYG!

Well, that's it for this update. There is always more, but it's almost 11pm with an early 4:30 wakeup tomorrow. Hope you have enjoyed the new info. Thanks for stopping by to check up on us! Happy Easter to all.

Continuing to (Re) Build Production

2009-02-20T13:11:00.000-08:00

Hello again, and thanks for checking back in on us. In this update:
1. Hypertherm Powermax 1000 Plasma Torch
2. Compressed Air Filter/Dryer
3. Floating Torch Holder
4. Bridgeport Mill
5. Builder Updates
6. The 25 Year Old Macintosh Plus

Here are the details:
1. Hypertherm Powermax 1000 Plasma Torch - After a long and patient search we finally located the plasma torch that we were looking for. We found it for sale on Craigslist in the Sacramento area. Hypertherm is one of the original plasma torch manufacturers and they make an excellent product. The Powermax 1000 has a great range of cutting capability with the current adjustable from 20 amps to 60 amps. This should give us the ability to cut thin 0.040 aluminum sheet all the way up to 1/2" thick steel plate.

The first order of business was converting the handheld torch to a machine torch set-up. Using some ideas from the internet this was a pretty straightforward conversion. It turned out very well at a much, much lower cost than purchasing a new machine torch and leads. A new machine torch setup runs $600-$800 and we accomplished this conversion for ~$20.

Now we just need to purchase some new tips and consumables for the machine torch. Hypertherm is making a new line of consumables that they call their "Thin Cut" tips. They have been having good success with these tips and they have apparently been getting good reviews from customers. More on that when we get the machine cutting some metal.

2. Compressed Air Filter/Dryer - Reading the forums about plasma cutting, it has become readily apparent that you have to have dry air to have good success cutting with plasma and to get decent consumable life. To that end we bought a desiccant air dryer, a filter, regulator and bunch of air plumbing to come up with this application. It's all mounted on a recycled teletype cart to provide an "all-in-one" place for the torch box, filter/dryer, and cords, etc. In addition to this setup, we spent a day plumbing compressed air to the other side of the shop to supply the air to this cart. Another day was spent running an 8 gauge 40 amp electrical circuit over to the other side of the shop to supply power to the plasma torch. 3. Floating Torch Holder - In preparation for adding the automatic torch height control, we need to have a floating torch holder. These are for sale online, but some cost as much as $1700. Using ideas gathered from several designs found online, we put together our own torch holder. Here are some pics of the assembly. Just before leaving for work this last time the UPS truck delivered the leadscrew and stepper motor that will do the Z axis movement. Here's a rough idea of how the leadscrew will be placed into the unit:Once we finish the torch holder the next step will be to purchase the auto height control electronics and software and convert our TM1 table to a Mach3 table. We'll still use the TM motor control box, but it will now be controlled by the Mach3 software. This setup will give us true, digital, full 3D toolcut path capability (and arc voltage height control). More to follow on this.

4. Bridgeport Mill - Since buying the company from George, he as been telling us that we need to have a mill. Well, recently a buddy called and said that he'd found a "smokin' deal" on a mill on Craigslist. To make a long story short, after renting a drop deck trailer and and putting in and 18 hr day (that included a trip to the San Franciso Bay area), we now have a gently used Bridgeport mill. While it still needs to get hooked up to 3-phase power (need a rotary phase converter) and we need to get the necessary tooling - we now have a mill. Overall, it seems that the mill is in great condition for the price - with just a few minor repairs (and a good cleaning) needed. So far we've spent a day cleaning the lower part of the mill, lubricating the ways, and getting the DRO (digital read out) to work. The DRO sensors were very dirty and needed alignment, but now work great. This tool will be invaluable in producing parts for our first aircraft and is a necessity for making the accessory gear drive and PSRU parts for the engine. More to follow.

5. Builder Updates - Our biggest news on the builder front is that we have had some great conversations with Bud Tedesco, the owner of Kit #16. Bud reports that he is almost completed but has a few items to complete before his first flight. He is hoping to do his maiden flight by the end of 2009. Here are some pix from Bud:

Great work Bud! We also got Bud hooked up with our Yahoo Prowlerbuildersgroup and look forward to learning a lot from him on building the Prowler. Congrats Bud and we are all looking forward to your first flight. Thanks for joining the group.

There has been a lot going on with all the builders recently. We now have had some kind of contact with owners of all but 5 of the original 16 kits that George produced. Recent info:

Kit #1 & Kit #13 - Rick is proceeding with his plans for his two planes. Check out his latest info here: http://www.rocket-boys.com/prowler.htm . Rick has gathered a great collection of Prowler info on his site. Check it out.
Kit #5 - Currently owned by George Morse. It is still for sale. You can see pix of this aircraft on Rick's site (above).
Kit #7 - Bryan Davies is still making good progress. His work lately has focused on several re-designs to address issues that George had made us aware of and issues from several builders. These include the tailwheel strut, a negative G mod to the fuse-to-wing junction, hyd cylinder attach brackets for the MLG. More to follow on these - but thanks for the great work on these areas Bryan!
Kit #10 - Ray is continuing to make great progress on his airplane. He's recently installed autopilot servo motors and is working on his avionics/panel installation. He just received his UMA engine gauges and reports that they are very nice units.
Kit #11 - Ben is in the process of gathering up all of the outstanding parts he needs after completing an inventory of his kit. He is working with Bryan to buy many of the parts he needs that Bryan has available. The rest we will be working on with Ben in the coming months.
Kit #12 - Chuck should have recently flown his airplane for about an hour. He was planning to do it in the next couple of days as reported by Ray. We'll report more when we hear about the flight.
Kit #13 - See Kit #1 above.
Kit #14 - Steve has fixed the issues with his Prowler that came up in the initial flights. He should now be able to enjoy flying the plane and the hard work that went into building it. Congrats Steve.
Kit #16 - Welcome Bud. See above.
Kit #17 - Cabi has been doing a lot of work on creating his drawings for using his plasma cutter to cut his wing spar parts. In a recent email from him he says that he was about to strap a Sharpie to his plasma table and test draw his wing spar parts to check them for accuracy. We'll report more on this later. On another note, Cabi will be part of a feature article in the March issue of "Flying". He is also going to be in a BBC production on the U2 which will air this summer in July. Keep an eye out for that. Nice work Cabi.
Kit #18 - These jokers can't seem to get anything done on their airplane. Seems that they've been blowing all their time and money trying to get some defunct kit airplane company going again. What are they thinkin'??

6. Macintosh Plus - When we got the company assets from George one of the items included was an old Macintosh Plus computer. By "old" we mean really "old." Do you remember "boot disks?" Well, there was also a pile of old 3-1/2" floppy disks. Turns out that there is some good info on some of these disks. Mostly it is just good "history" info that may someday be useful. In any event, we're spending any "extra" time we have (yeah - right) to print out these old files. Using this old clunker has given us renewed appreciation for today's computers. It takes about 15 disk swaps and 15 minutes to print out just one average sized file on the old Macintosh dot matrix printer. But, it's also kinda fun - like archeology.

Thanks for stopping by.

Happy New Year From Prowler - Big News!

2009-01-16T11:31:00.000-08:00

As we begin 2009, we have some big news to share about Prowler kit and aircraft purchases.

In this post:
1. Purchase of kit #11
2. Purchase of the Red/White & Blue aircraft and kit #13.
3. CNC update
4. Builder reference pix
5. Builder Updates

Thanks for checking in and let's get started:

1. Purchase of kit #11 - According to our records, the "Old" Prowler Aviation produced 16 aircraft kits. These kits varied in completeness. Some were complete kits, several were not all that complete. In any event, kit #11 was a fairly complete kit owned by an individual in Prescott AZ. This kit was posted for sale on Barnstormers late last year and was purchased by Mr. Ben Armen. Ben is an airline captain living in PA. He as since taken possession of the kit, set up for initial assembly in Austin, TX, and has inventoried the entire kit. Ben has lined up assistance from old friends in Austin that will be helping him get started on his kit. Congratulations Ben. We look forward to working with you and assisting you in the building of your airplane.

2. Purchase of RW&B aircraft and kit #13 - As we previously reported, the second flying Prowler (Red, White & Blue aircraft) was owned by an individual in Jacksonville, FL. This person also owned kit#13. Mr. Rick Pellicciotti of Memphis, TN has purchased the kit, the aircraft and all of the Prowler parts and pieces from the JAX owner. Rick and his wife have moved all the Prowler "stuff" to Memphis and he has begun his inventory as well. Here are some pix of the move:

See Rick's website link (on the right side bar) for more information. We look forward to working with you and assisting you in getting your aircraft back together and kit built. We will post more about his plans once he gets his inventory done and has had an opportunity to come up with a game plan. Welcome aboard Rick.

3' Progress on CNC table - We have been spending a lot of time "burning electrons" on CNCzone.com (a great resource) and are getting a lot smarter about CNC tables and plasma cutting. As a result we have determined several modifications and options that we must add to our CNC table. The list includes: 1) add cable guides; 2) modify torch holder from a "manual" torch system to a "machine" torch system; 3) add an automatic torch height control system; 4) actually purchase and add the plasma torch to the table. Well, we took baby steps on this one and started with the easy one first:

Cable guides are now installed and table tested. No more wires hanging off the ceiling!! The torch holder system mod is up next. Here's the "manual" torch holder before removal:
We are investigating modifying this to a "machine" torch holder that will also be able to be used with the torch height control system. More to follow. Here's a pic of the current setup:

4. Builder Reference Pictures - Over the past several months we have had the opportunity to visit and work with builder Ray Seim. He has made his collection of Prowler pictures available to us for other builders to use as reference when working on their aircraft. These photos are of several of the completed aircraft and current kits at various stages of construction. It also contains many pix of single components being constructed which are very useful for builder reference. We have spent hours scanning and organizing these pix into a CD to distribute to our current builders. Many thanks to Ray for these photos, we really do appreciate this contribution. These will, without a doubt, be very valuable to our current and future builders!

5. Builder Updates - Here's a recap of the current builders that we have had contact with and the status of each aircraft:

Kit #1 (RW&B Aircraft) - Recently purchased by Rick and is currently being inventoried and developing a game plan to re-install engine and get the aircraft flying again.
Kit #5 - We recently discovered that George's 3rd aircraft appears to be kit #5 that was returned by a former owner. Airplane is airworthy, has flown, but is currently in "storage" and is for sale.
Kit #7 - This kit belongs to Bryan and has the wing almost completed. Bryan is getting ready to begin assembling the fuselage.
Kit #10 - This kit is owned by Ray and is in the 80% complete range. He is currently working on installing avionics and hopes to get the engine installed by the end of the year.
Kit #11 - This kit was recently purchased by Ben and has been moved to Austin, TX where it has been completely inventoried. Assembly will begin over the next several months.
Kit #12 - This kit is owned by Chuck and has flown. He is working on taking care of some issues and preparing another round of test flights.
Kit #13 - This kit was purchased by Rick at the same time that he bought the RW&B airplane. This kit is (in his words) "the 75% complete and 75% left to go phase." Inventory is underway and he will have a plan for this kit in the future.
Kit #14 - This is the airplane owned by Steve and has flown it's maiden flight with some follow on test flights. At last contact, Steve said he was working on some cooling issues and would be flying it again soon. That was late last year and we need to check in on Steve again soon.
Kit #17 (Sort-of) - This aircraft is being built by John "Cabi" Cabigas. We are calling this kit #17 since John purchased many left-over inventory parts as well as the engine and landing gear from George prior to our purchase of Prowler Aviation. His aircraft will be a collection of these parts, parts that Cabi is fabricating himself, and possibly some from us. Since it is still following George's techniques we are including it into the "Old" Prowler Aviation kits - as we are also doing with our kit.
Kit #18 - This is the kit that we are building. As mentioned above, we are including it in the "Old" Prowler Aviation kits since we are also using some left-over inventory parts from the old Prowler as well as our own parts that we are fabricating using George's techniques. Once we are actually set up for production - we will most likely switch to using some new kit numbering scheme. More to follow. We have a vert stab sub-kit that is being assembled and the wing spar is in progress. Total work probably represents less that 5% complete.

That's the latest and greatest. We work full time on this project when we're not working the "day jobs" so that we can get this company back up and running. We appreciate your keeping tabs on us and your support. Have a great 2009!

THE PROWLER GOES DIGITAL

2008-11-23T08:02:00.000-08:00

The topics of today's post: We've got a CNC table, Builder Contact.

CNC Background - After building the sub-kit for the Vert Stab recently, my focus in NorCal has shifted to getting the wing spar (center section and outter sections) into the wing jig. While Dave is back in FL practicing his riveting so he can start the vert stab assembly, I have run into the need to fabricate several steel pieces for the wing spar. Faced with the prospect of having to hack these parts out buy hand or trying to get set up to do these parts with a plasma cutter - we opted for the later.

If you recall, I mentioned in a previous post that John "Cabi" Cabigas is also building a Prowler. In fact, here's a link: http://prowlerjaguar.blogspot.com/ . Cabi bought a CNC plasma torch a while back and I contacted him about making some of these parts. Turns out, he had already modeled several of the parts that I need to have made. One of the biggest pieces is the wing attach plate that is bolted to the center wing spar and us used to attach the outter wings (at the spar). These are the pieces shown on the right here:

We found a day we both had some time and I went to visit him. We spent the better part of a day trying to flatten the "learning curve" on using his setup. The parts are still being worked on, but after seeing his machine work I realized that this is the way to go - when it comes to producing Prowler parts.

Buying The Table - Dave and I discussed this topic for some time, weighing the pros & cons. In the end we decided to pursue getting out own CNC plasma set up. We started looking at the different companies and their machines. We found that their systems vary wildly in both cost and capability. Cabi has a PlasmaCAM system. It's a good system that comes standard with many features that are options with other manufacturer's systems. In the end, we were leaning more toward the Torchmate system. We were going to purchase a new 4' x 12' TM1 system, but found a used 4' x 8' system for sale in Fresno, CA. After nearly a month of negotiations, we purchased the used system. Turns out, it was very well built, it was hardly even used, it was fairly priced, and it is expandable to a 4' x 12' system. Here are some pix:

The table came with the computer setup, but has had the hard drive reformated and a new operating system installed. The monitor has been replaced with an LCD monitor. We still have a lot more work to do before this becomes a useful tool in the Prowler shop. First off, we still have to purchase a plasma torch for it. I have been trying to learn how to use the software and I'm having some modest success. I have modeled my own "sample" part using the Torchmate CAD software. I have exported this file from the CAD software as a .dxf and then imported it into the Torchmate software that actually runs the machine. This software converts the "sample" part .dxf file into something called "G-code" which is what actaully makes the table move in the correct way to cut the part.

The Production Plan - While we were discussing the purchase of a CNC plasma system, we reviewed the parts breakdown of the Prowler and came to the determination that upwards of 95% of the basic airframe parts for the Prowler are made from 2 dimensional patterns. These parts are then either bent up into shape, or are in some way welded or attached to other pieces to form a larger part or assembly. So, our goal is to go forward and use this system to build our first airplane with the result that when we finish we will have modeled each part of the airplane for future use. Essentially we need to turn each of the patterns in these boxes:

into one of these (a sample part file in Torchmate software):
When we get ready to make another airframe, it should simply be a matter of putting the metal in the machine, pull up the files, and hit enter. Without having done any in-depth research, the hope is that we (using our system and Cabi's system) will be able to satisfy our production requirements - when we get to the point where we can start selling airframes.

Builder Contacts -
Ray Siem - We have stopped by again to visit Ray. He has made some significant progress on installing the systems back onto his airframe. He has installed the fuel and hydraulic systems. His main and tail landing gear are installed. He is in the process of making final decisions on his instrument panel and systems. Compare these pix with ones from a previous post:

Ray has an extensive collection of pictures that he has taken while working on his airplane. His pix are a collection of shots of George's , Chuck's, and his airplane. They are a great reference for building one of these airplanes from scratch. We are in the process of scanning all these pix into data files for computer storage.

Chuck Westcott - We have a meeting sked with Chuck for Tuesday, Nov 25th. He is based at the Salinas, CA airport and is planning on the second flight of his Prowler just after Thanksgiving Day. We hope to be there when it happens to learn as much as we can and document the occasion. More to follow.

Bryan Davies - Bryan's mother has passed away recently. Our sorrow and condolences go out to you for your loss Bryan. He has had to put the Prowler on hold for a while while he works on settling his mother's estate.

Steven Rogers - We (including Bryan Davies) had planned to go visit Steve in Sept, but had scheduling problems. Once Bryan is ready to go again, we will work out trying to schedule a visit to see Steve. We are really looking forward to the visit Steve!

That's the big stuff for now. Thanks again for checking in on us.

VISIT TO A BUILDER, WING SPAR PROGRESS

2008-09-21T07:05:00.000-07:00

The topics of today's post: A visit to a builder; building a drill press bench; and progress on our center wing spar pieces.

Builder Visit - One day last week while sitting on-call Todd took a trip to visit a another Prowler builder. He went to see Ray who is building one of George's original kits and lives near Thousand Oaks, CA. Ray has been working on his airplane on-and-off for some time now, but the quality of the work is astounding. His precision and attention to every detail is producing the best Prowler we've seen so far. Here is a pic of his airplane fuselage in one of his garages:

The airplane is actually much closer to completion than it looks here. This is because most of the rest of the airplane parts and systems have been completed, fitted, removed from the plane for painting and then stored in one of his many shelves of boxes. He is hoping to finish the re-assembly of all the components to the airplane and have it out of the jig within the next year.

Ray has been already been a wealth of information about this airplane and provided us with much more insight about the aircraft. After talking with him, we found out that another builder has flown his Prowler. Chuck is also a builder of one of George's original kits and is in the San Francisco Bay area. We look forward to getting together with Ray again many more times. Great work Ray!

Center Wing Spar Progress - Now that Dave has a sub-kit to keep him busy in his shop, Todd has had some time to work a little more on the wing in his. If you look back in the posts, it been almost a year since we cut out the pieces for the center wing spar. Hard to believe that this much time has gone by, but now we're making more progress. After cutting with a metal band saw, the edges of all the spar pieces are left with a fairly jagged edge, so they needed to be trimmed up. Here's a pic from last year's post: Also, the pieces were scribed to the pattern and then cut just outside of the scribe lines. This leaves enough material to file down the edges to a smooth finish. Turns out this represents a lot of filing. So, on to a better way.

Sometime after cutting out the spar pieces last year, we mounted a router under one of our building tables and fitted it with a 3 blade, carbide tipped router bit with roller bearing on the end. This provides for a technique to clean up the edges of our spar pieces (raw stock) and make them match the patterns exactly.
Here's how it works:
1) Mount the router and put it in the straight cutting bit;

2) Cut two 1/4" spacer strips for each pattern. One spacer strip goes under the entire stack and provides room to have a counter-sunk bolt head. The other is to provide room between the roller bearing (that rides on the pattern) and the actual cutting part of the bit . This keeps the pattern a good distance from the cutting edges and prevents chewing up he pattern. See pic in item 4 below.
3) Drill selected holes into the raw stock using the pattern/drill guide:
4) bolt the "stack" together and adjust the router depth to get the correct height for the pattern to ride on the roller-bearing: 5) Make a ba-zillion tiny bits of aluminum foil and end up with the whole stack looking like this:
The next item to work on are the bearing blocks. They are rectangular blocks that surround the bearing and are clamped under the wing attach brackets.

Drill Press Bench - A small side project that needed to be done was to create a long bench with a drill press attached for drilling the numerous holes that must be drilled into each wing spar piece. A long bench is need to provide support for these floppy pieces of stock while being drilled. This was the solution we came up with:
By mounting the drill deck (table) under the bench top the drill can just penetrate into the bench top and (most importantly) the head of the drill press is now height adjustable above the bench top buy loosening the drill deck handle and adjusting it.
Make sure to square the head of the drill press to the bench top. We used a tri-square and make adjustments (shims if necessary) to get the press square to the bench top in both directions. It has worked great.
Another side project that is getting more and more necessary is a hardware/parts bin rack. We found an old bread rack dolly for $10 and have begun modifying it for parts bins.

Contacts - Todd and Bryan were supposed to go up to Seattle to meet with Steve who has the 4th flying Prowler this weekend. Unfortunately, scheduling issue came up and we weren't able to coordinate. We are going to try to resked the visit for sometime in Oct.

Thanks for checking in on us.

VERTICAL STAB & MORE

2008-09-10T13:37:00.000-07:00

Welcome! Or, if you're keeping tabs on us, Welcome Back!

Well, we're managing to get another update done - and it's only been weeks, not months! But, that's because things are happening! Here goes:

Inventory & Parts List - It's taken several months to complete, but we now have a fairly accurate and fairly complete inventory of all the "stuff" we got from George. We have organized this information into a set of Parts List spreadsheets for the airplane. We now have one comprehensive document that contains information about each and every part of the airplane, what its name is, what it's pattern or template is, what it's material specification is, etc., etc. There will be changes, additions and subtractions to this set of documents as we progress, but it is a baseline to start from. Amazingly, this had never been done before, and until now all this information was scattered about in various places - or just didn't exist.

One of the biggest challenges was going through all of the old documentation and finding items that were represented as one part, but were actually made from several different parts and pre-assembled. For example, there is a short shaft that the gear are mounted to. It is "anchored" in the torque box and protrudes through the wing spar. In the old documentation, this was represented as one item. It is actually made from 8 different pieces of raw stock. For production, this information is important to know because it will affect material ordering, etc. Now we will be able to tell exactly how much 4130 (0.063) sheet steel is required for one airplane, for example.

During this process, we also accomplished two additional tasks: 1) matched up any left-over inventory with the patterns that they came from; and 2) divided all the inventory, parts, patterns etc. into seperate boxes (for now) for quick reference. So, we now also have a fairly accturate list of inventory we got from George in the sale and now know where to find it!
Vertical Stabilizer Sub-Kit - Armed with the new spreadsheets, we now have an idea of what inventory items currently exists in each sub-kit and what we will need to fabricate to complete an airplane. The first sub-kit on the list was the vertical stabilizer. Turns out that we had all but about 4 parts we needed to pre-assemble this sub-kit. As mentioned in the website, Todd is the "Production Guy" and Dave is the "Assembly Guy." The vert stab sub-kit has been produced and is now in final assembly. Dave will be doing a major over-haul on the assembly manual as he completes each sub-kit. So, in the end we will have a completely revamped builder's assembly manual.

The parts which needed fabrication included the vert stab skin, a mid-rib, a forward spar and a small angle clip. We used a vacuum bagging technique to fold and crease the skin, a break for the spar parts and the old fashioned "bang it out" technique for the mid-rib.

George came out to help get us started and guide us through the "jigging" process the first time.

Once that was done we drilled the skin and built a crate to ship it to the "Assembly Guy" - Ah, I mean Dave. Now it's on to the fabricatiion and pre-assembly of the horizontal Stabilizer sub-kit next.

Materials For the Plane - Over the past several weeks we have been sifting through the newly created spreadsheets and determining materials that need to be ordered to complete the first two groups of sub-kits. This material has been amassed and is now holding down a bench in the production shop.
This is the steel sheets, steel tubing, bearings, hardware, etc., needed to assemble the Tail Group Sub-Kits and the Wing Group 1 Sub-kits. Hard to believe, or maybe not, that including shipping this pile of stuff represents over $1K worth of materials. In some cases there is enough material to make more than 1 airplane, but some things have to be bought in a minimum order - so that's what ya get.

Contacts - We have contacted a few gents recently that are currently building, or have built a Prowler. In fact, we are going to visit Ray in the Thousand Oaks, CA area to see his project tomorrow (Sunday, Sept 14th). We can't wait, as he sounds like a really nice fellow. We have been very encouraged by some of the information Ray has given us with reference to the airplane, and several folks he's been involved with for the past (nearly) 20 years who know the Prowler and have information about it. We're sure we'll have a lot of info to put into a blog post after meeting with him. Much more to follow.

Also, as mentioned in an earlier post, we have been in contact with Stephen in Seattle area who has a flying Prowler. Bryan and Todd are going to visit with him on the weekend of Sept 20th. This is sure to be a major event in the process of expanding our knowledge of this airplane. Steve is an engineer in the field of airplanes and should have a lot of pertinent information to help us. Much more to follow here as well.

Thanks for stopping by. We'll try to get a post out after meeting the two fellows and tell ya what we found.

WOW - HAS IT REALLY BEEN 8 MONTHS!?!?

2008-08-06T21:09:00.000-07:00

We received an email the other day from someone wondering if we were still working on this project. Well, the short answer is definitely - YES! For the long answer, keep reading.

OK - let's see if we can account for all the time that has passed without an update.

December to March - Most of this time was consumed by our day jobs. Both Todd & Dave recently moved to new positions and/or aircraft at the day job and a significant portion of our personal time went to completing training, etc. Oh, yeah, Christmas was in there too!

April to May - More of maxing out on the day job to help pay the bills. Most of the rest of available time was devoted to personal projects that needed to be done (stupid honey-do's).

June to Present - Day job is at peak of summer travel season, so guess what!?!? Yep, more of maxing out the day job. However, by taking advantage of as much down-time as possible, we have made a large amount of progress on aspects of "(re)building the company". So, even though we haven't gotten a great deal of work done on "building the airplane" - we have made great headway on understanding the processes involved with producing Prowler parts and then how they are assembled.

We have gone through almost every component of the tail and wing. We've analyzed and cataloged each piece and then considered how to mass produce each one. We've identified many possible simplifications and improvements that we will incorporate into our airplanes. Much of this work was done in collaboration with Bryan (see builder list) and we thank him for sharing his experiences and ideas.

This work will continue with the fuselage parts in the weeks ahead, but it's a pretty time consuming and intensive process. Also, since Bryan has not yet started his fuselage, we don't have the benefit of his experiences - so most things become more of a "what if" discussion.

All of this has an important purpose, and we'll keep most of this to ourselves for now - but suffice it to say that there is "solid" "works" in the Prowler's future.
We also managed to get a few days in at AirVenture 2008.

A Few More Highlights -

Bryan's Airplane: Bryan is making very good progress on his Prowler. He recently had a Tech Counselor review his work in preparation for closing up his wing. Here is a write-up that was published on his EAA Chapter's website:

http://www.eaa182.org/Brag%20Book%20Photos/Prowler/Prowlerproject.htm

Here is a pic of his wing (Top):

Here is a pic of his wing (Bottom):

Steve's Prowler - We've had some great email exchanges with Steve and look forward to more. We will be attempting to learn as much about Prowlers as we can with Steve's help. You might say that he is fairly skilled in the trade of engineering aircraft so we look forward to marveling at his insight. Here's a GREAT pic from his airplane's maiden flight:

George's Airplane Move - George has decided to move out of his hangar. So, we offered him storage in one of our sheds. Here are a few pics of "move-in day."

Here is a video of an engine maintenance run 5 weeks later:

This video was taken with a digital camera instead of a video camera, so you can see the camera "strobing" the prop. The prop is actually turnng around 1000-1200 rpm. You can see dust swirls as George cycles the prop. Believe us, there is a LOT of air moving behind that prop!

BTW - This airplane is FOR SALE. If you are interested, please send an email on the Contact Page of our website and we will put you in touch with George. Since it is George's personal aircraft, we will not even try to answer any questions about the airplane. We're sure that you'll understand why we say that for all of our sakes - "You'll have to talk to him." We will put you in contact with him.

The Look Ahead - Well, the busy summer travel season is drawing to a close and Sept is usually a slow month in the airline business. So, we will endeavor to get a few things done around the shop. We did get hardware at AirVenture this year to bolt and rivet the center section main wing spar together, so that is next on the agenda. We are also going to endeavor to assemble the Vert. Stab. Sub-Kit and "ship" it out to ourselves for assembly. Dave will be working on that in Fla. while Todd works on the wing spars in Cal. Of course, there is always more part cataloging of the fuselage to help keep "free time" to a bare minimum. Oh, yeah, did I ever mention 3 great kids.......

That's all the news for now. Thanks for stopping by to check out our blog. We'll try get back to making this a more regular event.

ORGANIZATION AND A HUMBLE BEGINING!!!!

2007-11-15T12:00:00.001-08:00

This (pic) has really helped with the organization. These shelves are full of all the rudder, elevator, horz & vert stab, and some fuselage patterns. There are also some misc engine parts, gear parts, etc. but that will be sorted out as time goes by.

Here is a set of rolling shelves that were built to hold all of our hydraulic press patterns. These male/female dies are for pressing out bulkhead, wing rib, and some fuselage parts. The press is just on the other side of the wall to the right. Should be handy access for these heavy pieces.

WELL - FINALLY!!!! This is the humble start to our first Prowler. This is the first piece we cut from our heavy aluminum sheets. It's the center wing section main spar web. The jig saws all went south on us and they were slow anyway. I found the recip saw to be faster and easier to control and not drag shavings along to scratch the stock. It's still the HARD way to do this!

BTW - that's the "Old Master" back at it again. George just turned 80 years old recently. Wow.

This is the "somewhat" easier way to cut out all the spar pieces. We used George's metal band saw. It's somewhat easier, but it's becoming clear that there is no really "easy" way to cut this stuff quickly and practically (unless you have millions of $$ for the CNC 5' X 12' router tables).
This is laying out the fly cut for the torque tube hole in the end of the spar web. The torque tube for the gear will pass thru a bearing in this hole to support the top of the gear strut.

And... The fly cuts.

Here is the semi finished product.

What this makes is essentially an aluminum I-beam. The several laminations of strips at the top and bottom create the "flanges" and the shear web will hold it all together. When positive G's go on the wing, the top spar cap "flange" goes into compression and the bottom spar cap goes into tension. Negative G's have the oppisite effect. The whole assembly provides for the attachement of all the other wing components and gives the wing it's ultimate strength. Right now, all the pieces have rough sawed edges and must be clamped to spacer blocks and the original patterns. This assembly is then passed by a router that will clean up the edges and make the pieces all precisely the same as the original pattern. That will be the topic for the next post. Thanks for stopping by.

LATEST FROM PROWLER AVIATION

2007-09-29T16:20:00.000-07:00

Well, it may not be readily apparent, but there has been a lot going on here at Prowler Aviation the past 6-8 weeks.
FIRST - HAPPY BIRTHDAYS! September 2007 is the end of our second year as the new Prowler Aviation. We have made our last payment to George and now truly own the company. September also saw a big milestone for George. He celebrated his 80th birthday this past month with his family in Santa Cruz. Happy Birthday George!
SECOND - DAY JOBS! Both Dave and I are looking at upcoming training at work. Dave is currently in upgrade training for the A320 and I will be transitioning to the A320 sometime in December. We've both been working a lot in a effort to keep this project funded.
THIRD - SET-UP AND ORGANIZATION. The shop has been getting some final touches to get ready for building our first aircraft. I added several sections of base cabinets and a counter top for "clean" work and a double tub laundry sink for clean up.

I also have building lots of shelves and other organizational storage places. In this pic you can see the shelves for hand tools between the garage doors. There are more just out of sight in this pic. Also note the wing jig off to the right side of the pic.

I also fashioned together an aluminum storage rack that also doubles as a pattern holder for all the wing spar patterns and drill jigs. Here you can see where the 4' x 12' sheets stand vertically in the storage cart.

And here you can see the storage for the wing spar patterns and jigs.

FOURTH - ALUMINUM IS ON THE WAY! We have ordered all the aluminum we will need to build the first Prowler. We actually thought we got the first part of our shipments on Sept 25th.

Turns out this was actually a shipment of stainless steel that was destined for a company in Germantown, WI. A transposing of the last two numbers of a work order number caused it to end up at the shop by accident. It was pretty stuff, but stainless tends to make for very heavy airplanes!It has since been re-packed and delivered back to the trucking company. Our 3 deliveries will all be picked up on Oct 2nd. Wing spar building will begin soon.

AirVenture and Prowler Nite

2007-08-11T08:06:00.001-07:00

Well, it was another great year at AirVenture 2007. The weather didn't always cooperate, but everyone made the best of it. Got to see a lot of incredible airplanes. Some of the notable ones were: Cabi's U2, Ruff Stuff (P-38), Glacier Girl (P-38), Big Bossman (F7F), and many others.

Unfortunatley, no Prowler's were present - YET! Maybe next year!?! We did, however, sponsor an unoffical "Prowler Nite" at the Camp Scholler campground. Bryan Davies and I were able to set up his RV and our camper side by side. In the space in between, we had a cookout and invited Prowler folks, friends and family on Wed nite.

We had a great time meeting all of you and talking Prowlers for the evening.

Thanks to all of you that were able to attend. We look forward to more get-togethers in the future.

Prowler Shop Gets Even Cooler!

2007-07-15T06:56:00.000-07:00

During my last few days off of work I was able to spend 2 days camping in the Lassen National Forest with the family, and 3+ days doing the final assembly of an evaporative cooling unit for the shop.

Since the days are now regularly in the high 90's and low 100's, it's become somewhat of a priority to get some cool air into the shop.

It's taken a while (note the date of the first pic) since I started welding together the frame for holding up the unit to the side of the building.

But the results were worth the wait. I had a few minor setbacks during the project, but was able to find workable solutions around the issues.

Here you can see the hole for the air to enter the building. I would have liked to take out the studs, but since I didn't originally expect to mount the cooler here, the structure wouldn't support the weight of the unit if I took them out - at least not without a lot of re-building of the wall.

So the studs stayed, but with little sheet metal leading edges mounted to the front side of the studs (gotta think areodyamics!). In the end, it doesn't affect the flow much at all.

Also, to distrubute the weight of the system there is a 3"x3"x12' angle iron on the inside of the building lagged into each stud and the window headers above the windows. There are four 3/8" allthreads that carry the load from the outside into that angle iron on the inside. And the stand on the outside is lagged into the studs at serval places.
-
As I test ran the system the first time, the shop cooled to 78F with an outside air temp of 98-99F. So the math and science of this swamp cooler thing really does work! (see previous post).

So, here it is pretty much complete. I need to tack the small supply line and bleeder lines to the wall and paint them to match the outside. Then it will be complete on the outside.

On the inside I only have the unit wired temporarily off of an outlet. I still need to run a new circuit off of the circuit panel, but that will wait until after AirVenture.

ALMOST FORGOT

2007-06-23T13:47:00.001-07:00

HYDRAULIC PRESS UPDATE:

Sometime in early June there was some time available to put the hydraulic press that we had acquired from George back together. After getting the hydraulic ram re-built and tested it needed to be reinstalled into the press and have the top and bottom beds re-installed. It may not be visible in these pics, but there is a 1/2 inch piece of plate steel inbetween the frame and the wooden bed on the top and the bottom. The one on the bottom is even more massive because of the large stiffening flanges that are welded to the collar and the 1/2 inch plate steel. The collar merely sits on top of the hydraulic piston. The ram is actually a 50 ton bottle jack that has an auxillary port.

Via that aux port you can put pressurized hydraulic fluid directly under the piston and run the press. For now, it is just operating with the jack via the jack handle - you know, the old fashioned way! But it's good enough to allow for testing temporarily. Sometime

in the fall we will build a small hydraulic power

pack to run the press more practically. During our test runs we will look to see how much pressure is required to press the pieces that we need to make. This will determine how big (psi) system we will need. As you might image, it also determines how much $$$ it will take to build that system - the higher the PSI the more the $$$ needed to build it.

TIME TO UPDATE THE SKED

2007-06-23T13:28:00.000-07:00

If you look back to the last "Updated Plan" I think you'll find most of the items that were layed out there have been completed. There are a few exceptions - begining the wing assembly being the most notable. However, it's always good to have goals, so here are ours:

JUN '07:
1. Finish installing Evaporative cooling unit.
2. Work the day job to make $$ and time-off in JUL for AirVenture.

JUL '07:
1. Work the day job to pay for AirVenture in AUG.
2. Family vacation(s).
3. AirVenture! The entire week!

AUG '07
1. Locate, buy, and ship (or go get) the majority of the metal needed to build our Prowler.
2. Work the day job to pay for AirVenture and metal (see #1.)
3. Begin work in earnest to build parts of our first Prowler:
Dave - Rudder, Elevator, Horz Stab, Vert Stab
Todd - Wing

SEP '07
1. Continue work outlined above.
2. Build a hydraulic power system for the press.
3. Squeeze in time for Reno.

OCT '07
1. Build a better retaining wall and water drainage system behind the shop.

Hot News - IT'S HOT!!

2007-06-23T12:20:00.000-07:00

It's been a while since the last post. Longer than planned, but we have both been working a lot at the real (day) jobs in an effort to keep our financial houses in order.

Since the last post, it has gotten pretty warm in northern Calif. Typical summer - hot and dry during the days. The nights are much cooler - mid 60's currently. In any event, the shop is in need of daytime cooling. So there is now a window a/c unit permanently installed between the office windows. It was a modest 2 day project in all. Next up is cooling for the main shop floor. Word around here is that evaporative "swamp" cooling is the way to go. So late last year Home Depot had the last remaining units (mostly damaged) on close out. I got a really good deal on this unit and picked it up.

One of the louvered panels was damaged, but was easily replaced by calling Champion. Total cost for the new unit: less than $90 without the motor. The motor and a few other parts will provide cool air for the main shop floor for less than $200. After talking with a few folks with more "swamp cooling" knowledge than us, we finally decided on a place to install the unit. It's going to be on the exterior north wall with the entry hole cut just under the ceiling.

With some odds-n-ends angle iron laying around, we fashioned up a bracket to hold the unit to the wall. This is a pic of the outside support system.

On the inside will be an 8-10 foot angle iron (3 inch flanges) to distribute the approximate 450 lbs load along more of the wall. The inside and outside supports will be lagged into the wall studs, and then the two halves will be bolted together at several places with all-thread through the entire wall.

In the last pic (below) the 20"x20" duct will enter the shop centered on the windows and from the top of the wall down to about where the clock is.

Evaporative cooling works well in this area because of the low relative humidity.

Theororetically, an evaporative cooling unit can cool air from it's ambient (dry-bulb) temp down to it's 100% humid (wet bulb) temp. Like any system there is never perfect efficiency, but a well maintained unit can achieve 70% efficiency.
We did a recent sample calculation using current weather.com data and found:
Dry bulb temp: 99 deg Farh.
Wet bulb temp: 65 deg Farh.
Air temp entering shop = 99 - .70(99-65) = 75.8

Not too bad. Unlike A/C however, you don't try to recycle air in a "swamp cooler" system. You actually have to provide about 2 sq. ft. of open window for each 1000 CFM of air moved in order to maintain proper temp and fan motor loading. More later.

SHOP PASSED FINAL INSPECTION TODAY!

2007-05-18T21:40:00.000-07:00

The Prower Aviation - West shop achieved a milestone today by passing the county's final inspection. We are getting much closer to working "IN" the shop, instead of "ON" the shop!

Some last minute work on painting and exterior trim boards (not for girly men)!

The Front

The North Side

I will try to have a more detailed update posted sometime in the next week.
Thanks for looking.