Elevator Trim Tab - HELP!!

[CDBridgesRV7A]

Good Day All,

I seem to have run into a wee problem. I just re-made the trim tab hinge for the 3rd time so now the elevator trim tab is ready to be riveted. The plans say to start with the bottom side, however how do you set those 426 3-3.5 rivets that attach to the trim tab spar? Once everything is clecoed together I can't get to the shop heads to set those rivets. Do you use flush pop rivets?

Thanks for the help.

Cheers

Chris

 

[lorne green]

My trim tab is riveted with AN426-3's. I think; don't really remember because I finished this part years ago but
you have to rivet the top before you bend the trailing edge. I think. Good luck, Chris.

 

[paul330]

I believe the trim tab is similar if not identical to the -10. If so, the spar is S-shaped. So you cleco on the bottom and rivet it by easing the skin apart and then cleco on and rivet the top. Make sure you rivet in a random pattern or you will introduce a warp.

The -10 has 2 trim tabs - I bought a total of 6 .....

 

[Flyfalcons]

Cleco the bottom only first. I used this step as my excuse to pick up a longeron yoke for my squeezer and all went well.

 

[cbkillion]

I did the bottom of mine first but could only reach the first three on each edge before the yoke didn't have enough reach. Instead of buying a new yoke which could just reach over the spar, I bent the top skin away enough to just squeeze the back rivet set in there and then back riveted the remaining rivets on the bottom. Pretty easy, and no deformation. Just be sure to use a lot of pressure so the skin immediately around the rivets being back riveted are flat to the plate below.

See here: Riveting the trim tab.

 

[rapid_ascent]

I just completed my 2nd trim tab over the weekend and I saw the description you are talking about in the plans. You have to just cleco the bottom of the spar to the skin then set those rivets. Once the bottom is set you can install the rest of the clecos and rivet it closed.

I used my longeron yoke to reach around the spar. I tried other combinations but you just cant reach them all. With the longeron yoke just start setting the rivets from one end and remove the clecos as you go. It probably only took me 15 minutes to set of of those rivets. If you have a little block of wood wedged in to hold the skin open a little it seems to help.