Sunday, July 15, 2007

Prowler Shop Gets Even Cooler!


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.
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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.
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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.
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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.
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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.
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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.
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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).
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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.
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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.
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Saturday, June 23, 2007

ALMOST FORGOT

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

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!!

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.

Friday, May 18, 2007

SHOP PASSED FINAL INSPECTION TODAY!

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.

Wednesday, April 11, 2007

ANOTHER UPDATE

Sorry it has been a while since the last post. A lot of work has been happening, and we have opted to keep the work going in lieu of sitting down to mash the buttons to do an update. Finally, however, we've reached a short lull in the activity so it's time to get busy update the blog.
Here (in no particular order) are progress items that we have recently accomplished:

SHOP WORK

The push is on to finish the Prowler Aviation West shop. The most recent development is the role of the CDF (California Dept of Forestry) Fire Department. Turns out that because of the potential for wild fires in Nothern California, the building inspectors will not even come out to do a final inspection until you get the "Good to Go" from the CDF. Getting the nod from the CDF is not as easy as it would first appear. Turns out, you must have all the brush (mostly Manzanita) cleared out to a minimum of 100 ft from ALL of your buildings and structures (not just the building you are having inspected). Oh, oh. You must also have the trees trimmed up to 8-10 ff from the ground. OK. They are also not big fans of having tall grass growning under your decks. Ugh. So, several days in the past couple of weeks have been spent cutting & burning.






Before











During












After

Grass and weeds are next.






Handrails have been added, downspouts installed and trim boards painted.








Still have exterior window trims to put up, some painting to do, and one exterior light to put up.
Hope to pass the final building inspection before the end of April '07.





AIRPLANE WORK

Wing Jig - Recently took the time to research and begin assembly of our wing jig. The wing is assembled suspended on 6 posts with the leading edge pointed down. The two end posts attach at the tip ribs. The 4 posts in the middle are not yet complete because we don't have the wing spar pattern completed yet. We have to have the entire wing spar (or at least a full scale pattern of one) in order to get the exact placement of the middle 4 posts. Two of the middle posts attach at the main gear bays and the other two posts attach just outboard of the landing gear torque boxes and just inboard of the junction between the center wing section and the outboard wing sections. These two have the most critical placement. We used a large beam laying on its side for the main center part of the jig. This can also be made from simple tubing, but we happened to have this available at no cost, so we used it.



Drill Press - One tool that we will be using is a drill press. So, the time was right and the money available so a trip to the local Lowe's netted a Delta 16" Drill Press. Really haven't had much of a chance to use it yet, but no doubt it will be a most useful tool in the years to come!



Hydraulic Press - The hydraulic cylinder has been taken to a hydraulics shop and has been rebuilt and tested. The ram had been leaking and needed service. It is now back in the press. Next items up on this area:
1. Build a hydraulic power pack to run the ram. We did get a power system with the press but there are a few problems with it. We are considering whether it is more cost effective to rebuild the old or just buy/build new. Leaning toward the latter.
2. Rebuild the press tables and install them into the press.
3. Test the system for pressure, leaks, etc.
4. Run some tests to see if the system will press out wing ribs, fuselage parts, etc.


Patterns, Parts, and Jigs - We recently began starting to inventory all of the parts, patterns and jigs that we got in the sale from Mr. Morse. We decided to start on the Empanage first for a few reasons. Most importantly, these are somewhat smaller components and Dave will be able to work on them at his place while Todd starts on the wing. Here you see the parts of the tail end of the airplane. Lower right are the rudder parts, lower left are the horizontal stab, middle left is the vertical stab, and above that are the elevator parts. At the middle right are aft fuselage parts and along the top are parts still un-inventoried. Not show are the skin patterns that are too big to fit them all on the table.

Drawings and Documentation - All the drawings that we obtained as part of the purchase of Prowler Aviation have been unrolled, uncoiled, unfolded and stacked on a large table in the center of the office. It measures somewhere in the vacinity of 5-6" thick. The other documentation (binders, books, etc.) are filling a medium sized bookcase. There are also somewhere near 100 or so 3" floppy disks that go with the Apple Macintosh that we got from George. At this point, we're not sure if it will take longer to re-learn how to use a computer that requires "boot discs" or go through all the data on all those disks. It could be close. You can see that computer sitting on top of the desk in one of the early pictures posted below.

Business Cards, Hats, and T-shirts - Now that we got our new logo from the graphic desinger, we have designed and ordered our new business cards, ballcaps and T-shirts.









These were made at http://www.printsmadeeasy.com/. It's a very well organized and easy site to use to design your own business cards. You can upload any graphics that you like. For about $22 a pack of 100 shows up in about 3-4 business days.

The shirts are on order, but have not been delivered yet. We'll get a pic or two in another update.

Thanks for checking out our site and our blog.

Saturday, February 17, 2007

Updated Plan

Feb '07
1. Continue sorting through all of the documentation from George
(Manuals, plans, drawings, etc.).
2. Locate nearest supplier of sheet aluminum.
3. Install downspouts.

Mar '07
1. Build a wing jig.
2. Get hydraulic cylinder rebuilt.
3. Rebuild the press and motor/pump.
4. Layout and cut wing ribs.
5. Practice press forming the wing ribs.
6. Finish shop construction and get final inspection.

Apr '07
1. Collaborate w/ Cabi to layout and cut wing spars.
2. Begin assembling the wing.