I spent way too much time researching the wing attach fittings from every angle. I even called Bob Barrows and spoke with him. I now have a very good idea of the sequence I need to follow and the things to avoid. I got out my drilling guide and enlarged the 3/16ths holes in the spar fittings to 1/4 inch. I used my drill guide to keep things straight. I first drilled 13/64ths, then 15/64ths. After that, I used a step reamer I have. It has a 15/64ths bit as the pilot and 1/4 inch reamer behind. The bit followed the hole precisely and helped line up the reamer. I only have one shot at drilling the spars, so I’m just creeping up on it. The wing attach fittings are drilled to 1/4 inch, so an AN4 bolt is perfect. I may have to remake the .090 reinforcing plate for the front fitting as the coping for the tube is a bit too deep. I still have time to decide after all is installed. They are one of the last things to put on.
