Dad continued with the arm rest reinforcements. Jig drilled the end and centre locations and then rivet fan from there.
A spacer was made to be used between the two surfaces which means the parts can be clamped together tightly.
Then it is clamp and drill. If you are doing something similar to this - take care the lower structure is as far aft as possible, we used #41 drills to start with until everything looked OK.
Then of course there is the 'other side' to be done - this is the P1 side.
We chose to go with 'oops' rivets (AD4 shank with AN426AD3 heads) as the bottom structure had been previously drilled & dimpled for AD3s which made alignment slightly harder.
The external rivets to the skin need dimpling - this is a slow process with the pull dimples but it does work.
The finished internal layout - upper will be CS AD3 blind rivets, lower will be AN426AD3s.
The external layout - just looks like an extra line - someone would have to be pretty up with RVs to notice the difference externally.
Meanwhile I looked at a shelf for some of the avionics. Currently we don't know the exact shape / size because we haven't got the parts yet (probably about 6 weeks away). However I do know that some instruments need to be mounted level and in line, therefore some preparation can be done.
This is a sheet of 0.040" (slightly thicker than most of the AL sheet that we generally use) and will get precision drilled for the cockpit ribs and folded for strength / stiffness.
This was the first fitting / location check - should work well.
Then it was bending the forward edge. In preference I would prefer to clamp the main surface and bend the tab, however clamping the surface was next to impossible so I had to clamp the tab. This resulted in a bit of mild 'hammering' marks but all came out in the end.
The stopping point for today. The outboard edges and aft edge all need to be bent, but I'll wait for some of the instruments first in case size / layout makes a difference.
