The elevator control horn was my first piece. I had some trouble drilling the rivet holes trough the pre-drilled pilot hols of the control horn and rib because my right angle drill was too large. This caused me to make one of the pilot holes offset by about 1/64". I bought a right angle adapter and some "stubby" bits. This made drilling the rest of these holes very easy. Step drilling up to 1/8" and some carefull reaming made the hole nice and round, and still small enough to rivet.
You'll notice that 3 hours seems long for clamping preformed parts and some drilling. Well the preformed ribs weren't perfectly formed, so I had to adjust the bend angles. The short bend was pretty far off, and I didn't notice that it was supposed to be more than 90 degrees until after I had already drilled holes in the rib. It's hard to explain, but I had made the short bend flush with it's corresponding edge of the control horn assuming the rib's flange would extend past the edge. Once I realized that this was incorrect, and bent the angle correctly, I discovered that the rib actually extended 1/32" farther than ideal, maybe a little less. This is probably well within tolorance, but will keep this in mind during assembly of the elevators.
I'm not riveting this together yet because I want to prime all the non-inspectable internal parts with zinc oxide.
