Hours: 5.9
Elevators: 21.2

I got a lot done today. All the skins are match-drilled and all the holes in all the parts (except for the skins) are deburred.

I was surprised this evening to find one of the pre-punched holes in one of the elevator skin out of alignment. It was a full 1/16" out. The other three skins were correct. I assumed at first that I had messed something up, but it wasn't me this time.

There is a series of pictures below which illustrate what I found and how I dealt with it.
Figure #1, Clecos in the skin and a ruler show the alignment issue.
The problem was painfully clear while final-drilling. After thinking it through, I knew I would have to drill the hole where it was - one way or another, so I drilled into the rib, knowing I'd have to deal with it again.

Figure #2, The rib with the bad hole. The top-left of the mangled hole is where Van's expected the hole on the skin to be. The bottom-right of the mangled hole is where the hole in the skin actually was.
My solution was to take some scrap aluminum and make a little plate to go over the messed up hole. I first positioned it over the messed up part of the rib, clamped it, and match-drilled to the hole I knew was matched to the skin. I then match drilled another hole to hold the plate to the rib, deburred, dimpled and riveted the plate to the rib with a flush rivet.

 Figure #3, Plate only with the hole matched to the skin.

Figure #4, Plate riveted to the rib.
Figure #5, Rib shown with side that will be against skin.  The lower right part of the hole looks ragged because of reflections, etc, but isn't.  This is where the remains of the wrong hole is.  After dimpling the hole in the correct location, I smoothed the points and thoroughly deburred and smoothed the edges of the holes.
Figure #6, Rib with hole moved to match skin clecoed in place.
The last thing I did was to mark the outside of the skin so I remember to use a longer rivet when the time comes.

No comments:

Post a Comment