tips for trim tab bending?

n701vb · Post by **n701vb** » Wed Jul 11, 2007 11:50 am

OK - Looking for tips to ensure I bend the tabs correctly on the elevator trim and left elevator skin.

I thought about using a hand seamer to get the bend at least started in the right place. Has anyone tried that? I would think that would work better than using a piece of scrap wood to get the bend started.

Thanks,
Vince

Post by **Spike** » Wed Jul 11, 2007 1:00 pm

See if you can find someone with a brake. I have friend who owns an AC shop and he has an electromagnetic hand brake that worked perfectly. Someone around probably has one you can use.

Spike

Post by **bullojm1** » Wed Jul 11, 2007 1:08 pm

Vince,
I consider myself somewhat of an expert on the trim tab, as it took me 4 tries to get it right! On the first three, I tried the bending of the tabs trick. It turned out OK, but never great. On the 4th try, cut off the tabs on the trim tab skin I made some "riblets" to go in the ends. I was so impressed with the riblet approach I cut the bent skins I had on the elevator and replaced it with a riblet.

If I haven't swayed you to the riblet way, then I will give you my advice on bending the skin. Get some dense oak wood (avail at Home Depot) to make some bending blocks. Use carpet tape to stick it to the elevator/trim tab skin and clamp the hell out of it. You don't need to pre-bend it, but take a piece of 1"x6" pine board and line it up parallel to the bend line on the flange. Use a hammer to hit the pine to evenly force the flange to fold down. Finally, use a flush rivet set in your rivet gun on low pressure (5-15 psi, start low and work yourself up) to finish off the bend.

Good luck with whatever method you choose. I documented both ways on my builders log, located at http://rvplane.com/?categoryid=2&dayid=107

Have fun!

svanarts · Post by **svanarts** » Wed Jul 11, 2007 2:35 pm

Mike's got a good idea here. I'd go with riblets. I know a few other builders who did it this way. I did not and it looks like my trim tab was assembled by an angry bear. In fact, it was. I'll probably rebuild the trim tab before I paint it.

cjensen · Post by **cjensen** » Wed Jul 11, 2007 2:51 pm

I used riblets, and it worked out great!

Mark Browning · Post by **Mark Browning** » Wed Jul 11, 2007 3:22 pm

I took a long time preparing to bend the trim tab on the elevator and made a half decent job, better than some RV'S I have looked at.
I read some where that some owners leave the trim slightly up or down when parked so the un even gap is not so obvious.
When I hooked up the Trim tab to the elevator my gap was not parallel

This bugged me for over eighteen months until I cut off the tab and fabricated a rib.
It looks perfect now. I won’t have any issues when RV builders inspect my tabs as they all do!

n701vb · Post by **n701vb** » Wed Jul 11, 2007 4:03 pm

Thanks, you have me convinced. Riblets are the way to go! Anybody have some pretty pictures I can go by? I saw Mike's and they looked good.

Vince

cjensen · Post by **cjensen** » Wed Jul 11, 2007 4:08 pm

The pics I have are of the elevator side, but it's the same thing...

Actually, looking back at my pics, I guess I did bend the tabs on the trim tab.

Oh well, the riblet is the same concept on the elevator.