Sun May 18 2008

Match drilling aft fuselage

Today Kody came over. After we got the fuselage completely leveled up so there was zero twist, we took turns match drilling the skins to the bulkheads.

After dropping him back off at his house, I match drilled the J channels to the side skins. I used a different method than just marking a line 5/16 inch from the edge. I wanted to ensure the J channels were centered in the middle of the cutout in the bulkheads. What I did is this: at each J channel, I pushed it up as far as it could go and marked a circle on the J channel through the hole in the skin. Then I moved it down as far as it could go and marked another circle. Then I positioned it in the middle of those two circles (I could see the very bottom edge of the top circle and the very top edge of the bottom circle) and marked a circle in the holes on either side of the bulkhead hole. Then I just held it in position with my hand and (being very careful not to drill my fingers) drilled through the skin into the J channel. I could watch the holes on either side of where I was drilling to make sure I didn't inadvertently move the J channel up or down. Pop a cleco in and move to the next bulkhead.

After repeating this process at all the bulkheads, I drilled the halfway point between them. Then halfway between those...and half again, etc, etc until I had a cleco every third or fourth hole. Then it was just zip, zap, whappety bap down the whole length of the J channel drilling all the remaining holes.

I actually finished up all the drilling after midnight. It came out quite well.

A view from the outside. Tomorrow I'll probably take this apart, and get started on trimming the ends of the J channels or deburring the whole shebang.