Do I need elevator trim tabs????

jtrollin · #1 03-18-2009, 05:16 PM

I am about to ruin another elevator trim tab.. I can not figure out how to rivet the darn thing together. For the life of me I can not figure out how to get around the spar to rivet that together and the trim horns are impossible... I tried a squeezer but the skin is to thin of metal and it went all to heck..

I am tempted to pay someone to build the darn things for me because the frustration they have already caused...

Any hints or tips on these stupid things?

thanks and sorry for the rant

Auburntsts · #2 03-18-2009, 05:29 PM

John,
I had to have a helper hold the skins open as I finagled the squeezer around the horns, but got it done. As for the spar, I think I used my longeron yoke for those rivets. If you don't have one, you're welcome to borrow mine. If you're around Sat, maybe we can meet at KHEF or someplace convenient to both of us.

jtrollin · #3 03-18-2009, 05:38 PM

I had to order new spars as I ruined those so I will not be ready this weekend.. I think the kit should come with enough parts to make 4 trim tabs that way two might come out correct...

I need a beer!

Auburntsts · #4 03-18-2009, 05:42 PM

Well, I'm between kits so you can borrow the yoke whenever you want, just let me know. Maybe the next Chapter meeting would be a good time.

flion · #5 03-19-2009, 12:53 AM

It will be a while until I get to that point, but I have looked at the trim tab skins and spar and I am planning to use the method I used on the trim tab for my -6A. That is, I will tape the rivets into the tab, put the spar in place, and then back-rivet them by putting the skin down on my back-riveting plate and peeling the top side open enough to get the set behind the spar. The horns complicate things, but I should be able to back-rivet them as well if I save them for last. Then, a quick squeeze on the trailing edge to make the top side lay against the spar and I should be able to use a squeezer to rivet that side - once the foam ribs are glued in, of course. On the -6A tab, I found I could get my hand in behind the spar in position to hold it down onto the skin (a finger on either side of the rivet) and use my knuckles to push the upper side up enough to get the set in. I know that step 4 on page 9-16 tells you to complete the trailing edge bend, but the skin is thin enough that you can peel it back easily without unbending it too much and it also re-bends easily (just don't do it over and over).

PJSeipel · #6 03-19-2009, 05:32 AM

Or you can cut the trim tab along the trailing edge bend, back rivet the skin to the spar, and then finish it up with the AEX wedge like the rest of the elevator trailing edge. Granted, Van's doesn't endorse the practice, but it looks better and is much easier to assemble. My second set of trim tabs, where I did the AEX wedge vice building them to plans, came out very nicely.

PJ Seipel
RV-10 #40032

wv4i · #7 03-19-2009, 06:12 AM

I built an RV10 tail and empennage kit nearly to completion before selling the project due day job and family committments. In short, and from experience, it's time to give your project a rest until you can restart it with experienced help to get thru the trim tab issue. Not worth getting stressed out over it. Hang in there.

jtrollin · #8 03-19-2009, 06:13 AM

Quote:

Originally Posted by PJSeipel

Or you can cut the trim tab along the trailing edge bend, back rivet the skin to the spar, and then finish it up with the AEX wedge like the rest of the elevator trailing edge. Granted, Van's doesn't endorse the practice, but it looks better and is much easier to assemble. My second set of trim tabs, where I did the AEX wedge vice building them to plans, came out very nicely.

PJ Seipel
RV-10 #40032

Do you have any pictures of this, it sounds like a more reasonable way to make these things?

Flandy10 · #9 03-19-2009, 10:11 AM

Quote:

Originally Posted by jtrollin

Do you have any pictures of this, it sounds like a more reasonable way to make these things?

The AEX wedge idea would definitely give a consistent look to the trailing edge, but I think (for me) that cutting the trim tab radius straight might be a challenge. A longeron yoke and a pneumatic squeezer is an easy way to rivet around the spars. I have built two sets of trim tabs that way (mine and a friends) and they both came out great. When you rivet the hinges on, a standard yoke with an extended set works great.

Two of my most used riveting tools are the longeron yoke and the tungsten bucking bar. Both are well worth the money.

jtrollin · #10 03-19-2009, 10:33 AM

How did you rivet the horns on with out the skin bending up into the horn. I have the problem where when I squeeze the rivet for the horn the difference in thickness causes the skin to deform and the dimple to almost reverse its self?