Elevators Not Quite Finished

Back to work on the elevators today…

I started by riveting the trailing edges. I used the same technique that I used with the rudder by partially back-riveting and then setting with a mushroom set.

I then set the remaining rivets aft of the rear spar. I couldn’t find good way to set the last rivet on the lower side so I ended up resorting to blind rivets here.

I then put a bend with the edge forming tool on the top skins of each leading edge prior to rolling the leading edges.

We used the same technique here as we did with the rudder. PVC pipe, duct tape, and a strap wrench. Amber applied the torque while I held the pipe down to the tabletop. This was challenging like it was with the rudder but we completed both of the elevators successfully.

I put the final bends in with my fingers, then clecoed, reamed to final size, and deburred.

Blind rivets in place. One step closer.

I then worked on the trim tab hinges. This starts by clecoing the first hole, aligning the hinge and match drilling the remaining holes. The same process is completed on the trim tab side of the hinge.

The left elevator came out great and everything is straight and well aligned.

When I started on the right elevator trim tab hinge I noticed some oil canning on the top skin panels on both sides of the shear clip.

After looking at things closely I determined that the top skin was slightly in compression from the rivets on the inboard rib. I think this happened because the clecos on the upper rear spar are not snug fitting (due to the countersinks on the thin flange) and there was a bit of play here when riveting the skin to the outer rib.

I decided to remove some of the rivets on the outer rib and I confirmed that this is where the compression was coming from. It is very subtle but a slight offset makes a big difference.

I ended up removing the remaining rivets in the inboard rib of the top skin and I’ll re-rivet these after I rivet the hinge in place along the rear spar. If I rivet working towards the inboard side of the elevator it appears that I should be able to remove that oil canning.

Saving that for another day..