How to Balance Ailerons

[Scotty G]

Hi gang,

My ailerons have a significant amount of paint on them after a recent paint job. I’ve looked in the drawings and build instructions I have (pilot, not the/a builder) and can’t find a procedure for balancing the ailerons. Can anyone point me in the right direction?

Thanks in advance.

[FinnFlyer]

Originally Posted by Scotty G

Hi gang,

My ailerons have a significant amount of paint on them after a recent paint job. I’ve looked in the drawings and build instructions I have (pilot, not the/a builder) and can’t find a procedure for balancing the ailerons. Can anyone point me in the right direction?

Thanks in advance.

Never heard of balancing ailerons.
One possibility is to place weights positioned on top of the 3/4" steel pipe until your find out how much is needed. Then measure out that weight in small lead pellets and epoxy resin, mix and pour into the steel pipe (aileron removed and standing on edge with the other end of the pipe plugged).
Or melt the lead in a can with propane torch and pour.

Finn

[BH1166]

You dont say which rv model you have. This or electronic trim is the solution. Seach vans web store maual aileron trim, -vs- trying to balance.

https://store.vansaircraft.com/rv-7-...t-ail-t79.html

[Carl Froehlich]

Recommend you do not do anything other than the per-plans counter weight pipe.

Balance is about flutter, not about static gravity balance. Adding more weight could push you the wrong direction.

Carl

[bjdecker]

Originally Posted by Scotty G

Hi gang,

My ailerons have a significant amount of paint on them after a recent paint job. I’ve looked in the drawings and build instructions I have (pilot, not the/a builder) and can’t find a procedure for balancing the ailerons. Can anyone point me in the right direction?

Thanks in advance.

What problem are you experiencing?

[Scotty G]

Originally Posted by BH1166

You dont say which rv model you have. This or electronic trim is the solution. Seach vans web store maual aileron trim, -vs- trying to balance.

https://store.vansaircraft.com/rv-7-...t-ail-t79.html

Uh, no.

I posted in the RV-8 forum, so I have an RV-8.

The problem isn’t trim; I have aileron trim and it functions fine. The change occurred when the paint job happened.

The shop put on an insane amount of material on the ailerons, and it’s changed their balance. (According to forum rules, I can’t name the shop publicly, but I’m happy to warn anyone away from the privately. It’s a Arizona shop, not in Eloy.)

The ailerons will ‘bounce’ between left and right in light turbulence and above. I damp it out after about three oscillations - but it wasn’t like that before. I have not tried it undamped by my hand.

It’s clear to me that the additional weight of the paint on the ailerons, aft of the hinge and no longer in check with the leading edge counterweight (if any), is out of whack.

So I’m looking to check what is going on and define the problem before I come up with any solutions.

[bjdecker]

Originally Posted by Scotty G

...
So I’m looking to check what is going on and define the problem before I come up with any solutions.

Good call -- hand fly it and see what's what first. The oscillation you describe sounds more like the autopilot "hunting" (i.e. the roll gain is too high)...

B

[Scotty G]

Maybe I’m speaking Portuguese…

Although I do have an autopilot, I didn’t mention it yet because I don’t use it very much, and it may mask the problem.

The problem happens while hand flying in turbulence.

By saying I have not tried it “undamped by me,” I mean I have not had it occur without my hand on the stick.

I’d say there is a small range in the flush/wings level area that is a little dead zone. You get the ailerons moving in turbulence, and the ailerons break out “uncommanded” a little bit and cause a left-right-left wobble that I can damp out. But it’s like there is a force driving the ailerons out of flush, it excites a little, I damp it out, and I go on.

I have no way of measuring what the stick force is to damp and correct, but it’s super light and easy to do. Probably around a pound of force or less. Which tells me, if my ailerons are unbalanced, it’s not by much.

It’s almost like neutral static stability in the first breakout instant, then I can easily damp it. Kinda like power steering that’s way too sensitive.

It wasn’t this way before, and I believe it’s because there is more weight from paint on the ailerons aft of the hinge, and this now equals or outweighs any counterweight that may or may not be in the leading edge.

Hopefully that is more clear.

[PilotjohnS]

If it was me, i would disconnect each aileron pushrod and see if it flops trailing edge down. If so i would use a scale and push up on the aileron and see how much force it takes to push it up.
If the trailing edge flops up, i would not worry too much.
Either way i would call Vans once you know how much it is “heavy”

[danny]

Doesn't sound like you've called Van's about this. Might be worth a try.
danny