Flap Support Frame
To drill a hole in the flap support frame tube for the flap return spring anchor tube, I used a drill centering jig. I built the jig that was described in the summer 95 beartraks issue. One change I made was to weld on 1/4" spacers which allowed me to run the tube long for welding from the back side and still be able to get it back out of the jig. Also notice that I didn't bolt the top of the mounting bracket, as I have already drilled my holes in the capstrips and spars and will match drill the top hole in the bracket upon assembly.
After welding in the tube I made sure it was level using a combination square. Again I made the tube extra long and will sand off later. To keep the return spring retaining washers located for welding, I drilled a hole in a piece of 1/8" aluminum, cut it in half, and used it as a spacer.