Since the front spar has already been drilled, the aft spar drilling will define incidence between the two wings as well as sweep forward and aft. A digital level will be used to measure incidence. The Avipro manual suggests using a wood block between the spars, but I couldn't find a completely flat one. So I used a 32 inch length of 1 inch angle iron, which I secured to the level using a pair of countersunk screws. I put a bit of teflon tape on both ends so as to not mar the finish. A measuring tape is used to measure the diagonal length from the tail, so as to determine sweep. I made a homemade .025 inch aluminum "fender" washer to keep the tape attached to the tail bolt. I wanted to use the Avipro drill guide, but Mark Goldberg was already on his way to Oshkosh, so he couldn't ship it. Since I didn't want to wait until he came back and shipped it to me, I went ahead and fabricated a successor to the Avipro, which uses a set screw to lock the reversed drill bit in place, so that two people aren't needed to use the guide.
Angle iron screwed onto digital level.
100 ft tape secured to tailpost with homemade washer.
