General Wing Assembly:
2. Perhaps the most critical single step towards assuring success in the accurate assembly of the wing is this one. The goal now is to ensure that rib W2 is absolutely square to the rest of the assembly. Rib W2 serves as the reference to which all other parts will be aligned.
a. Double-check that rib W2 is still directly above where it is drawn on the plans.
b. Set one of the laminated spruce spars (Spar A) on top of the ribs, with the shorter length on the bottom, and such that the shorter section extends between 3/8 – 1/2” beyond where rib W7 is drawn on the plans. (This will allow a similar 3/8 – 1/2” extension beyond rib W1 at the wing centerline.) Therefore the laminated 1/4 x 1/4" section runs from beyond W1 through beyond W7, and the 1/8 x 1/4" section runs from just outside W7 through W10 (or W10a).
c. From the front, insert a small carpenter’s square, or similar tool. Rest this as vertical as possible against the front jig rod and vertically align W2 to the wood base rails of the jig. Take small aluminum triangle square (or similar tool) and ensure that the length of the rib is 90-degrees to the jig rods. You can also sight the side of the rib to the reference lines on the plans. When satisfied that W2 is true, fully seat Spar A into the cutout for W2. Only seat the Spar into the other ribs partially, as you will still need to move them into position, and do not want too much friction – either making it difficult to do so, or causing you to crack a rib. Double-check that W2 is still accurately aligned. When satisfied, apply a drop of thin CA on each side of the spar and rib. If carbon fiber (CF) rods are used, apply CA to bond the rib to the CF rods.
d. Repeat procedures
a through
c similarly for the bottom Spar A. (Please note that the shorter length of this bottom, laminated spar will be facing up.)