Trim Tab Hinges

Spent today getting the trim tab hinge match drilled to both the elevator and trim tab front spar. The two required pilot holes took awhile to get correct and it took two attempts. Fortunately the hinge was 3 ft. long which was 6" longer then needed so I had extra length to work with. The act of precisely centering a #40 hole, 3/16" from 2 adjacent edges, on an unwieldy part was harder then it first appeared. I'm sure there's an easier and quicker way to do it. Then I got a little too enthusiastic hammering a punch on the designated spot to center the drill bit that I bent the hinge. Sigh. I was able to cut off the damaged part and reattempt with better results. Then making sure the hinge was exactly parallel with the spars prior to drilling proved challenging as there wasn't a convenient way to accurately measure along the hinge length. It took multiple tweaking of the clamps before I was happy with the fit. Precision measuring can be a challenge with very small units. Yesterday I had to bend a close out tab on a skin to a 1/64" tolerance.