1 hr
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( 3 / 20 )I cut and glued in about half of the top diagonal braces for the ailerons. I also made an aileron end rib that will form the outboard end of the aileron. The full rib at that location will remain intact as part of the wing tip, so a separate rib for the aileron was required.
2 hr
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( 3 / 20 )With the wing flat on the table and the trailing edge along the fence, I glued the trailing edge to the aileron ribs after trimming the ribs to length.
1 hr
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( 3 / 20 )I cut a form block out of some scrap birch faced 3/4" high density particle board. After clamping the aluminum panel to the block, I used a dead-blow hammer to work the flanges for the side panel around the edges of the form block.
The curved top of the tank did cause out-of-plane warping which was more than a match for my metal shrinking skills (nil). I don't have fluting pliers either, so I modified the form block with a depression between each rivet hole on the top edge. After placing the side panel back on the form, I hammered flutes into the depressions. The sides are nice and straight again.
2 hr
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( 3.1 / 19 )I glued the tail section of the ribs onto the rear spar.
1 hr
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( 3 / 15 )After cutting the ribs into two at the rear spar point, I glued the center sections of the ribs to the front spar.
2 hr
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( 3 / 15 )Using the mylar patterns, I cut out the tank side panels and bottom from 0.040 5052 aluminum sheet. I roughed the parts out using a snips, then cleaned up the cuts with a laminate trimmer bit in the Dremel following a straight edge (or spline in the case of the curved top pieces).
3 hr
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( 3 / 19 )I designed and printed my wing tank pattern on mylar (dimensional stability). The tank is designed to fit above the drag bracing diagonals. The top of the tank forms the top skin of the wing. The tank fits inside a 14" wing bay, between the front and rear spars.
Each wing tank has a capacity of 7.25 gallons. In level flight at the stall angle of attack the sump will unport with just under two gallons in the tank. The aircraft will also have at least a 5 gallon header tank, so this is not a big concern. The tank should completely drain under cruise conditions.
The drawings do not show the location of the sump drain, drain fitting, filler fitting or vent fitting. I have purchased a flush type cap from Aircraft Spruce. I also bought my tank fittings there.
2 hr
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( 3 / 25 )After a considerable period of indecision, I have decided to make riveted aluminum fuel tanks for the RW-11. The wet wings of the RV series is made like this. R.S. Hoover (AKA VDubber) posted an informative article covering the basics. Several builder sites illustrate the steps involved. It looks do-able.
I thought about forming a "lost foam" mold out of polystyrene then wrapping it with glass impregnated with epoxy. But then I'd need to make a hotwire saw to get the airfoil shaped plug. I'd have to get set up to use laminating resin. All lame excuses, but it just didn't appeal to me.
I also considered a welded tank. Tom Marston (spelling) who flies a Dakota Hawk out of New Richmond, WI suggested these. He had his made for him, but I didn't care for the price. I do have an acetylene set-up, and I've watched the Kent White videos. With practice, I could probably manage it. However, I would like the top skin of the tank to form the top of the wing for that bay. I am not convinced I can make the tank without warping the top skin too much. Also, I am almost certain to face the frustration of leaks.
So I arrived at a riveted tank. A top skin, two rib shaped sides, and a wrap that covers the front, bottom and rear of the tank. Add a couple of baffles, a flush cap, and couple of fitting flanges for vent and outlet and it should set to go. The bottom of the tank is a couple of inches above the bottom of the wing to allow the drag/anti-drag strut to pass underneath. Each wing tank should have a volume of 7.5 gallons. Combined with a 5 gallon header, I should have 3.5 hours of fuel on board.
I was able to find 5052-H32 sheet aluminum in 0.032, 0.040, and 0.063 thicknesses from a local sheet metal fabricator. 5052 is the recommended material for fuel tanks. I'd read of people using everything from 0.025 up to 0.050 for tanks. 0.050 was recommended for top skins, lest they get banged up during filling operations. After feeling the 0.040, I decided that was plenty heavy. A 4x10 sheet cost be $90. I could have gotten away with 0.032 for everything but the top, but that would have cost me another $60, and saved me less than a pound.
I also ordered 1/8" Avex rivets - the same used on the CH601 - and a ProSeal clone. More as I move along - hopefully with pictures.
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( 3 / 45 )I spent the evening modifying the bell housing from my Corvair core. The manual from William Wynne, as well as half a dozen web sites, show how it is done. I used a bandsaw and then files and a grinder to clean mine up. Here is a picture of mine, ready to be blasted with walnut hulls:
1 hr
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( 3.6 / 40 )
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