NotMuchofaStall
Member
How were your holes for your elevator trailing edges? This is where you're using the pre-punched holes in the 0.016" elevator skin as a guide to drill #40 through the AEX wedge, bottom skin, and a length of angle. I'm having a heck of a time making the drilled hole concentric with the pre-punched hole, so I get misshapen holes.
I've already ruined my right elevator, so I'm using that as a test article for my technique while I await new parts (and a practice kit for further practice). I drill a 3/32" hole normal to the upper skin, then try to drill #40 through the parts all clamped together using my 84º drill guide block. The best hole I've made is about 0.118" in the upper skin on its widest aspect, larger than 0.103" per the mil-spec, and not concentric. I know the rivet will expand to fill the void, but that seems like a lot. I wouldn't accept that elsewhere on the airplane, and the trailing edges seem like a critical area. I know I'm drilling it at an angle, which will cause it to be somewhat elliptical, but I would expect the widest part of the hole to only occur in the fore-aft direction, and it's not consistently there.
Any tips or suggestions for how to drill these holes?
I've already ruined my right elevator, so I'm using that as a test article for my technique while I await new parts (and a practice kit for further practice). I drill a 3/32" hole normal to the upper skin, then try to drill #40 through the parts all clamped together using my 84º drill guide block. The best hole I've made is about 0.118" in the upper skin on its widest aspect, larger than 0.103" per the mil-spec, and not concentric. I know the rivet will expand to fill the void, but that seems like a lot. I wouldn't accept that elsewhere on the airplane, and the trailing edges seem like a critical area. I know I'm drilling it at an angle, which will cause it to be somewhat elliptical, but I would expect the widest part of the hole to only occur in the fore-aft direction, and it's not consistently there.
Any tips or suggestions for how to drill these holes?