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Wing Tip Spliting

AviatorJ

Well Known Member
Having a heavy wing issue. I corrected some of it by rerigging the right aileron which was off by a good 1/8-1/2 inch. I flew today and while it's much improved it's still heavy on the left side.

Looking at my wing tips, they're not aligned with the ailerons, which are aligned with the flaps, which are aligned with the bottom of the fuselage. There's no control surface twists either, all the rivets line up. Here are a few pictures.

Here's the right side -



Here's the left side, which isn't off as much -



To me it makes sense to correct the right one first. Go fly and if I then have a heavy right wing then correct the left one.

I'm not 100% sure on the technique used to do all this. I'm guessing you just dremel across and 'split' the trailing edge. Then pull it up where it's level with the aileron. Then drill some reference holes to cleco later. Sand the inside flox back together and cleco to dry.

Does that sound about right? If I cut too much off when splitting can I fill with milled fiberglass vs flox or maybe use some fabric?

Thanks!
 
You don't need to cut anything off. Just split it down the "fold".

That's exactly what I did. Cut it down the trailing edge and up the side. Pulled it into position, drilled and clecoed it. On the inside I put some fiberglass cloth to hold everything in position then filled the cut line with a mixture of micro.

Easy enough to do.
 
This is indeed a fairly simple fiberglass job, but don't expect to see much change in "roll".
Although it is far out on the wing and has the "arm", it is a small area and has little effect.
 
This is indeed a fairly simple fiberglass job, but don't expect to see much change in "roll".
Although it is far out on the wing and has the "arm", it is a small area and has little effect.

Exactly - - fix the heavy wing first then align the tips. My aileron alignment in flight was drastically reduced once the cause of the heavy wing was corrected, same on my 7 and a friends 10. So - fix the roll first or they won't be inline after you do anyway.
 
So based on those pictures there?s no thought that it may be causing me to roll left with my hands off the stick? This is with two full tanks and my aileron trim all the way to the right. Ball centered, straight and level.

My previous aileron adjustment improved it a bit.... maybe bring it up (right side) some more?
 
FWIW, on the -7 you can rotate the tip in the wing by more than you'd need to correct that much variation. Might be the same for the -10. It would obviously require redrilling the attachment holes.
 
Looking at my wing tips, they're not aligned with the ailerons, which are aligned with the flaps, which are aligned with the bottom of the fuselage. There's no control surface twists either, all the rivets line up. Here are a few pictures.
Thanks!

I suspect you know this, but the reference from which everything is rigged is the flaps in the reflex position. This is set by ensuring the flap is hard up against the rear wing spar and not when they are level with the fuse. They may or may not be level with the fuse when in the reflex position. You can confirm they are hitting the spar by removing the control rod from the flap.

Good luck addressing this.

Larry
 
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How does it fly with the same weight in each seat?....... and trim centered.

Not sure in the same seat, but with 20 gals out in the left tank and the aileron trim all the way to the right it's still wants to roll left. I'll do another aileron adjustment before correcting the wing tips.
 
Read carefully.

Not sure in the same seat, but with 20 gals out in the left tank and the aileron trim all the way to the right it's still wants to roll left. I'll do another aileron adjustment before correcting the wing tips.

Justin, 20 gallons is a pretty heavy wing. I would suggest you get and read the heavy wing document from Vans, then gather some data on twist of wings and ailerons for baseline. If all that is ok, then you likely have asymmetric aileron lift and will have to adjust your pivot points to correct it. The plane will fly straight and faster. Unfortunately, Vans has no blank inner hinge brackets, but the RV7 outer blanks can be modified to work just fine. There are some valid posts about the aileron height for the 10 that you can research in the journey for a balanced airplane.

It took me 8-10 flights on my 7 to get it dialed in and a friend had about the same on his 10. His now flies level and straight with no trim. The aileron tip alignment issue was nearly gone when it was all done.
 
You should do the following checks.

Level the plane, place a level on each flap and be sure that they have the same incidence. Do the same of the Ailerons. They should have the same incidence as each other and same as the flaps when retracted. The wing tips should line up with the ailerons. From your photo it looks like the right aileron has more miss alignment with the left, the miss alignment shown in the photos would cause the plane to roll left. Don't underestimate the affect of this. You could remove both wingtips and fly the plane and see if the wing heavy conditions remains.
 
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Properly built (no twist, consistent trailing edges) ailerons won't cause stick-free roll. They will neutralize to each other within the confines of other airframe misalignment. IIRC, Van's doc adresses that.
 
Not always simple ...

As others have said, there are several things to point at but starting off with the flaps and ailerons all set to reference and then setting the wingtips is the first place to start.

What you may find is that since you have already drilled and set the tips, even opening up the rear of the wingtip and pulling it into position will not make the tip align along the rear length length without cutting maybe a foot or two up the side of the tip as well.

If you just cut the tip rear edge, it may work or it may just pull the inboard side up leaving the outboard down which really won't work well unless the other side just happens to be the same way. It is easy to end up with the tip in alignment but the outboard tip still pointing down.

Just saying to check the whole thing before you start glassing it back. I assume you know you will have to pull out the small rib at the back and reset it after you adjust the tip.

Good luck.

Bill
 
Here is my fix

Guys I have done the maiden flights on about 10 RV10s over the years and THREE of those I have built. Each and everyone of these had a tendency to roll left. At the same time I would usually see the ball off to the right. Usually it would be trimmed fully right and one still needed quite a stick force to level it at high speeds.

Assuming that you have done the flap and aileron alignment correctly. Do not waste time at this stage to try and fix a slightly out wingtip. This will not fix the roll. It is cosmetic only. Got the T-shirt.

I would usually start by adding a 3D printed trim wedge on the left hand side of the rudder and also on the bottom trailing edge of the right aileron. About 12 inches long and about 1/2 inch high should do for both. You could use balsa as well. I use good quality double sided tape. This will reduce the left roll.

If this does not get you to no left roll - rotate the top intersection fairings in the clockwise direction, viewing from the top. In other words - steer the leading edges of both gear fairings to the right and the trailing edges to the left. Yes there will be some twist in the gear fairing now. You can test it by undoing the screws holding the top intersection fairing and then tape it with duct tape as a test. Worst case you end up with a few unused holes on the belly. With a bit of luck they will still be covered by the fairing.

Worked for me everytime. ;)
 
Any explanation for why rotating the gear leg fairings clockwise viewed from above wouldn't cause the plane to bank to the left (and also yaw left) even more? I'm having a hard time imagining that this brings about the effect needed to correct a left roll and left yaw. What's the aerodynamic explanation?
 
I was able to wrap up several other items I wanted to complete before tackling my heavy left wing issue. So now back on working through the heavy wing. Decided to hold off on the wing tip splitting until I get most if not all the heavy wing out.

I had a few hours today and ran over to once again recheck my flaps/ailerons. This time instead of leveling the plane in flying attitude and measuring the angle of both flaps... I decided to follow something I read on another post and measure the angle of the wing and then adjust the flaps at the middle so their -3 degree's above that. The challenge is the digital level I use is to the 10th of a degree. Various places on my wings were a few 10th up to half a degree off. I decided to use the middle rib on the flaps and use the lower part of the wing forward of that rib as a reference point. I also applied some moderate pressure on the bottom to simulate some wind, just forcing any slack out.

Good news is my right flap was exactly -3 degrees up from the wing. My left side however was more like -4 degrees. It's too early to tell but that could have decreased the lift in the left wing. Not sure how much lift .5 to 1 degree difference makes. We'll see I suppose.

I hope that helps to resolve it. To be honest the thought of having to tweak around my intersection pieces or adding some sort of tab sounds tricky.
 
Not sure how much lift .5 to 1 degree difference makes. We'll see I suppose.

It is a secondary effect and as such will help, but not much. Mine was 1-1.5 deg off on my 7.

Since the 10 trailing edges are fixed radius, then it is either a wedge or adjusting the hinges.

You can take a stirring straw - you know the small diameter? Take a piece of thin tape, and tape it about 1/2" from the TE on the underside of the light aileron midspan. Try the full 6" at first. That should provide some help. If so, then begin using a wedge in its place.

Or just understand the aileron position issues and repair them.

Disclaimer: be sure to do the above after eliminating all the other potential major issues, like twist, and flaps (like you are doing).
 
You can take a stirring straw - you know the small diameter? Take a piece of thin tape, and tape it about 1/2" from the TE on the underside of the light aileron midspan. Try the full 6" at first. That should provide some help. If so, then begin using a wedge in its place.

Crazy that something the size of a stirring straw could have an affect. If I do end up needing a wedge (Which I would rather do than remounting the aileron hinge point), where have most people sourced these from?
 
Rudder?

Just a shot in the dark here but is it possible that the rudder isn't rigged correctly? I have no experience to back up my thought here so take it for what cost you = <1Cent.
 
Crazy that something the size of a stirring straw could have an affect. If I do end up needing a wedge (Which I would rather do than remounting the aileron hinge point), where have most people sourced these from?

I used a small balsa piece that was pre-shaped into an aileron shape from the hobby store. Once sized, I put a coat of paint to seal it and then used silicone to adhere to the rudder and the under side of the aileron on my 6.

Larry
 
So that?s for a rudder, would something like that work for an aileron too?

Crappy weather so still haven?t flown. Also with my rerig my wingtips are only about 1/8? off or so. So at this point might not be worth the hassle to split them for cosmetic stuff

Rudders and ailerons and aerodynamically equivalent, they just operate on different axis'

Larry
 
Any explanation for why rotating the gear leg fairings clockwise viewed from above wouldn't cause the plane to bank to the left (and also yaw left) even more? I'm having a hard time imagining that this brings about the effect needed to correct a left roll and left yaw. What's the aerodynamic explanation?

Bill my view is that the gear fairings are acting like small rudders ahead of the center of pressure. So they act in reverse. Please note that I have said that you should fix yaw first as in getting the ball in the center before moving on to fix the roll problem.
 
Just to close out the thread. I've put on 7 or so hours of flying since I made all my adjustments. I STILL have heavy wing, however it seems to be better since AP can now handle turning right with no issues (used to have to help it some at 100% torque, now I have it at 80% and it's fine.)

I flew the other day and got to 5 gallons remaining on the left tank, right tank was full with 30 gallons. Even then I still had a slightly heavy left wing.

I'll keep fiddling with it but I guess not planning on splitting the wing anymore.
 
Okay here was how I resolved the heavy left wing issue. It took a number of test flights as I would make a change, fill the plane up, go fly...

I had fiddled with the ailerons enough that it was time to mess with the flaps. I could only measure them so many times with a digital level and then I just decided to make some adjustments. It's hard to accurately measure these on the ground because there's some play that gets removed by the air pressure in flight. I tried to simulate this by pulling up on the flaps but then maybe I'm pulling up too hard, or maybe not enough.

First thing I did was bring the right one up by a turn and a half of the rod end. This had a noticeable effect, but it wasn't near enough to resolve it. I did two adjustments on the left one, first I did a turn and a half and then later another full turn. This took out most of the heavy wing but it was still heavy and I couldn't remove it with the aileron trim.

I ordered a wedge from Cleaveland Tools and taped that under my right aileron after a fill up. Went and flew for an hour and a half and noticed practically all the heavy wing was gone. For the first time I was able to trim it out when I had a few gallons out of the left wing.

The last thing I did, which started this post was split the wingtip and reglass it even with the flap and aileron position. I did more than split it I had to drill out the rivets for the triangle piece, redrill new holes and re re-rivet. I also had to do a bit more fiberglass work because my cuts to split it weren't the best. Either way I got through and went flying.

ALL my heavy left wing is gone. With two people in the front I'm able to trim the plane out both in pitch and bank and fly no handed, with autopilot off. So in the end it seems that a combination of flap, aileron adjustments, a wedge and the wingtip splitting were needed in my case.
 
Not sure in the same seat, but with 20 gals out in the left tank and the aileron trim all the way to the right it's still wants to roll left. I'll do another aileron adjustment before correcting the wing tips.

Probably a good idea to disconnect your aileron trim springs while troubleshooting the heavy wing. Otherwise, the spring tension is masking the roll forces on the stick.
 
ALL my heavy left wing is gone. With two people in the front I'm able to trim the plane out both in pitch and bank and fly no handed, with autopilot off. So in the end it seems that a combination of flap, aileron adjustments, a wedge and the wingtip splitting were needed in my case.

Congrats on SUCCESS! I too had lots of little things. Doing the big one first really removes the masking of the smaller improvements.
 
Please note that on the 10 and 14 you need to clamp the elevators in the neutral position before aligning ailerons with the flaps. Due to the rigging of these aircraft the forward aft positions of the stick raises and lowers the ailerons a small amount.
 
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