Construction:
A - Ribs are Alloy 3003 .02 inch, folded over to 3/4 inch tabs
B - Anchor rib: Alloy 6061 .9mm
Rear leg doubled up with same material
Front leg doubled up with 1.1 mm by 3/4 inch bar, L-shaped to meet up with 1/2 tube, secured with clamp and glue
C - Spars are 35" each Alloy 6061 T-Section 5/8" X 1/2" X 1/20" Thk
Spars are bridged with 4" rectangles of Alloy 3003 .02 inch
D - Main tube is Alloy 38.5" 6063 .625" Od, .527" Id,
with inserted 36" Alloy 6063 .500" Od, .370" Id
E - Rear tube is 14" 6063 .625" Od, .527" Id,
with inserted 7.5" Alloy 6063 .500" Od, .370" Id
F - Skin is '0.86 gauge' Aluminum flashing material
Also:
Gurney lip is made with 35" each 1/2-inch L-shaped Alloy 6063 1/16" thick
Where tubes meet ribs, the junction is reinforced with a snap-on piece of PVC pipe, about 1/3-1/2 inch, secured all around with adhesive.
What I would (will) do different next time? The core of my wing's strength is two-fold. The I-beam that runs the length of it provides its rigidity, and next time I might use thicker aluminum between the top and lower T-shaped pieces, maybe reinforcing those with rivets. The 'anchor' of the whole thing is a path that goes from one upright, to the cross tube, and back to the other upright. This is the part that shouldn't fail even if the wing kinks and bends. Next time, I may do two complete tubes to double this strength.
Also, the aluminum I'm using for the skin is probably too thin. I love that it's light (and was cheap, since it's roofing flashing (US$40 for 50 feet of 24-inch wide aluminum). It's not a structural problem, since it's strong. But it dents too easily -- almost like fabric on the old biplanse, but more prone to dents.
And here's a shot of some of the extra last-minute reinforcements I did.
