What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Elevator TE folding probelms

Pooch

I'm New Here
Hello all,

I'm at the emp stage of my RV-7; after the stabs and rudder went together surprisingly issue-free, I'm having a bit of a problem with my elevators.

When I've folded them (using the usual hinged 8x2s), I've ended up with these unsightly and stress-raisery (I know that's not a word) looking bumps in the skin beyond the end of each stiffener.

I was interested in knowing if anyone had had similar issues and what the problem turned out to be?

Van's said I needed to trim down the end of my stiffeners more but having gone as far as squashing the elevator flat there isn't any interference between the ends of the stiffeners which makes me think it might not be that? :confused:

Anyway, some pics attached. Any input much appreciated.

Cheers











P.S. I know that rear most rivet has a horrible step on it. The rest of them are all much better!
 
Yes, I ran into this.

It's similar to the problem that they now discuss in Chapter 5 "Rib Flange Prep."

Unfortunately, the only way to fix this is a rebuild -- new skins, stiffeners.

The "pooch" is caused by the squared flat end of the stiffener just beyond the last rivet interfering with the skin as it gets squished in the 2X8 vice...

It looks like you can shorten the stiffener by 1/8 or more (watch edge distance to last rivet hole.), and then also dress the end of the stiffener - round up the edge where it contacts the skin.
 

Attachments

  • Screen Shot 2021-05-20 at 10.27.59 AM.png
    Screen Shot 2021-05-20 at 10.27.59 AM.png
    1.4 MB · Views: 64
Last edited:
Early on in my build I attended an EAA Sportair workshop for RV Assembly. Ken Scott from Van's was one of the instructors. When it came to using the 2x8 bending brake, he demonstrated by slamming the think shut on the practice flap we were building.
So my advice, don't be gentle with the 2x8 bending brake. Also, make sure the brake is not pushing the part out of the assembly as you squeeze.
 
Yes, I ran into this.

It's similar to the problem that they now discuss in Chapter 5 "Rib Flange Prep."

Unfortunately, the only way to fix this is a rebuild -- new skins, stiffeners.

The "pooch" is caused by the squared flat end of the stiffener just beyond the last rivet interfering with the skin as it gets squished in the 2X8 vice...

It looks like you can shorten the stiffener by 1/8 or more (watch edge distance to last rivet hole.), and then also dress the end of the stiffener - round up the edge where it contacts the skin.

Thanks very much Brian, I'll take all that advice on board.

I strongly suspected I'd be rebuilding them anyway.

I guess this is the frustrating part they talk about in the instructions, the rest has been an absolute pleasure!
 
It might be that you don't quite have a tight enough bend at the trailing edge. A straight edge should lay flat along the skin (parallel to the stiffeners) until it reaches the radius at the trailing edge. You might need to over bend it a little to get it right.
 
Back
Top