ORGANIZATION AND A HUMBLE BEGINING!!!!

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

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

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!

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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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.