We Had Pop In The Shop Again!

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

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!

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.