Build log documenting construction of my Van's RV-10 airplane.
Started RV-10 on June 29 2022.
Builder #42638
Van's OP-51 Sheet Metal Basics Practice Kit - 2nd Attempt
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Today I completed the Sheet Metal Basics practice kit that came with my RV-10 empennage kit that I received a few days ago. I compared this completed kit with another one I attempted a couple of months back to see if there were any differences. Overall, I think I did a better job this time around, or at least felt more comfortable working with the different tools, but this attempt was not without its gotchas outlined below. Read on...
Starting pieces
Skins drilled and match-drilled
My first gotcha came when reaming holes from a #40 to a #30. On one of the holes, the reamer slipped out and slid across the surface of the skin making a very minor but visible scratch. I wouldn't worry about this if it was on an actual skin, but something to pay attention to.
Angle piece cut and drilled...
...and match-drilled to skins
All parts deburred, dimpled, countersunk, cleaned and ready for riveting
My next two gotchas came in the final steps of skin preparation.
The first was was when I was upsizing a #40 hole to a #19 hole. I tried to upsize in one go and the resulting hole was not as round as I would have liked. I should really have used a drill press here, or upsized in intermediate steps.
The second gotcha occurred when countersinking the hole at the edge of the skin. For some reason the countersink ended up too deep. My guess is that the edge of the skin bent up slightly while I was pushing down to countersink (the cage was only seated on the skin on one side). This is something else to pay attention to when working on the real airplane.
Riveting complete outside...
...and inside
Another issue encountered during this build, which is not really a gotcha but something I need to figure out how to handle if it happens again, is that when tightening the screws into the nutplates, both screws became increasingly difficult to tighten. I managed to get them both in eventually, but the heads look a little worse for wear and the threads look somewhat stripped even though they appear to be holding well. I'm not sure what happened here because I haven't had this issue with other nutplates (and there were several on the light box) that I installed previously.
Comparison 1st attempt (left) and 2nd attempt (right)... outside
inside
and side
As I mentioned at the beginning, I think this attempt came out better than the first attempt... there is much less pillowing between the skins, and the flush rivets are more flush with the skins in general. I will, however, need to pay more attention to countersinking, upsizing holes and installing nutplate screws.
Lessons Learned
Pay attention to countersinking at the edge of a piece to ensure that the countersink doesn't end up too deep. Countersink small amounts each time and check.
Upsize holes in small steps or using a drill press with the piece securely clamped. I mentioned this before but didn't follow my own advice so here it is again!
