Gregg Brightwell

Gregg Brightwell

Well Known Member
Hello all, haven't posted in a while. I just finished building my left hand aileron. Alas, I am not sure if the skin wasn't trimmed perfect square, or if I just plain ole' goofed. The aileron is completed, and when set on a true-flat table, the inboard end of the trailing edge touches the table, and the outboard end is 3/16ths to a 1/4" off of the table. So, just less than a quarter inch of twist over better than a 4' span. I don't like it, but I don't know how much twist, if any, is 'ok'. Ideas?

Thanks,

Gregg
 
Build On!

My RV-6 has a similar twist in one aileron that I worried about all through the rest of the build. I think it sneaks - and locks - in when you rivet the wobbly end ribs to the steel nose pipe/counter balance - and everything else follows from that.

In practice though the plane flies beautifully "hands and feet off" with no "heavy wing". I did put a lot of time and effort into accurately rigging the empenage and wings to the fuselage though. Errors here probably have more effect on trim.

Jim Sharkey
 
Twist

Hi

I am not disputing what the guys say above, but when I clecoed mine together on the 4 I also found a twist.

I measured things up and found the bend had been put in out of square..... Vans sent me out some new skins bent correctly so now I have straight ailerons.

Obviously you can take the advice above or contact Vans.

Best
 
One minor downside

Greg,

The only down side I see ( very minor ) is that the twist may be noticible when installed on the wing i.e if the outboard end of the aileron is lined up nicely with the wing tip the inboard edge may not line up with the flap. Like others have said, more a cosmetic issue than anything else. Ive just finished my ailerons and they are the same as yours ( 3/16" twist ), for me if the twist is noticable ( if it bugs me ) when installed on the wing, I may do something to rectify.
 
How do you "fix" a heavy wing?

With just a little squeeze of the trailing edge...
If just a slightly sharper bend can change the balance, it sounds like proceeding with a bent control surface is begging for an offsetting fix somewhere else. Do-able? Probably. But the best solution for a bent rim on your car isn't necessarily to start bending another. I twisted one of my ailerons during build. Bruce at Vans encouraged me to build another. Just remember, any advice On the forum (mine included), is free and should be treated accordingly.
Terry, CFI
RV9A N323TP
 
Derek said:
Greg,

The only down side I see ( very minor ) is that the twist may be noticible when installed on the wing i.e if the outboard end of the aileron is lined up nicely with the wing tip the inboard edge may not line up with the flap. Like others have said, more a cosmetic issue than anything else. Ive just finished my ailerons and they are the same as yours ( 3/16" twist ), for me if the twist is noticable ( if it bugs me ) when installed on the wing, I may do something to rectify.
Click to expand...

Depends on the direction of the twist...

On most of the old style (-4 and -6) wing tips, the tip TE is about 3/16 out of alignment (tip molding high) anyway.

You may have just cancelled the error out....:)
 
Last edited:
Perhaps a silly question, but can you tell if the bend is incorrect BEFORE building the aileron? I am about to start the RH aileron now. It would seem at first glance that you could measure both ends from the leading edge (spar attach that is) to the radius of the bend. However, only 3/16th's out over 54"....? Looks like a couple thousanths could do that. If I COULD get a measurable difference, would Van's just send me a new skin based on that?

I followed the instructions on building the aileron.... I used weights, and made a conscious effort to NOT have any twist. I'd hate to build the other aileron and have the same result. The one thing that came to mind... I wonder, if there could have been any torsion load at all on the pipe counterweight when I riveted it to the nose ribs. That could induce a slight twist, I reckon...

At the end of the day, I do high quality work. I want to build these parts as good as I can build them. I'd just hate to 'do it right' and still get the twist.
 
Gregg Brightwell said:
Perhaps a silly question, but can you tell if the bend is incorrect BEFORE building the aileron? I am about to start the RH aileron now. It would seem at first glance that you could measure both ends from the leading edge (spar attach that is) to the radius of the bend. However, only 3/16th's out over 54"....? Looks like a couple thousanths could do that. If I COULD get a measurable difference, would Van's just send me a new skin based on that?

I followed the instructions on building the aileron.... I used weights, and made a conscious effort to NOT have any twist. I'd hate to build the other aileron and have the same result. The one thing that came to mind... I wonder, if there could have been any torsion load at all on the pipe counterweight when I riveted it to the nose ribs. That could induce a slight twist, I reckon...

At the end of the day, I do high quality work. I want to build these parts as good as I can build them. I'd just hate to 'do it right' and still get the twist.
Click to expand...

Make sure that you do all of the "drilling" and "fitting" - including of the nose pipe - with the ribs and top or bottom skin on a flat surface and you'll be fine.

Jim Sharkey
 
You won't be happy

With the twist in the left aileron. It will bug you every time you look at it.

Build the right one paying more attention to twist.

Then re-do the left one. Don't accept "good enough" at this stage of your
build.

My 2 cents

Bryan Carr
 
RH aileron dead straight...

Guys, this post started a few weeks ago with me having a slight twist in my LH aileron. Here is an update: I finished the RH aileron yesterday. I measured the skin before I started, and found the leading edge NOT square to the 'ends'. I have pics of this, and 2 different squares showing the skin out of square by about .060". MY aileron skins were also NOT prepunched like the manual says they are. There IS ACTUALLY a top and bottom! There is about a 16th" difference between the top and bottom dimensions.
Anyway, on this aileron, I squared the spar to the trailing edge, instead of the leading edge. This left a bit of excess material forward of the spar, but I still had the correct dimensions per the drawing. I built this aileron EXACTLY like the left one, on the SAME table. Guess what? Perfectly flat. No twist. Undoubtedly, I paid more attention to twist on this one, as I was expecting it, but I DO think the left hand aileron skin might have been twisted as well. At the end of the day, when I fit the ailerons onto the wings, and install the tips, I will see how it looks. If things don't line up, I'll build a new left one. Also, anyone out there building a -4, but haven't yet started ailerons? Look close at the skin, if they aren't punched, remember... there IS A top and bottom.

Happy building,

Gregg
 
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