Aileron Rigging

[Cmead]

We’ve got about 7 hours or so logged in the last couple of weeks. The aircraft sat for quite some time, about 10 or so years. Our right wing wants to dip in flight. We can correct with trim (electric) but when we put enough to compensate, it’s sbout at the mechanical limit of the system. So when we turn left, we only get about a 1/2” of addition aileron control. So, left side is up and right side down...pretty significantly. Our CG is good, 96.5 to 97 when loaded. When we did the W&B, right side was 15lbs heavier in the rear main. Very little “play” or slack in the system when one is held. 

So...should I adjust the ailerons and rig left up and right down some while the stick is centered? What kind of drag is this causing?

VEZE, O-235, seeing 145 it’s at 2400, no pants yet, silver bullet prop 

 

[Marc Zeitlin]

13 minutes ago, Cmead said:

Our right wing wants to dip in flight. We can correct with trim (electric) but when we put enough to compensate, it’s about at the mechanical limit of the system. So when we turn left, we only get about a 1/2” of addition aileron control. So, left side is up and right side down...pretty significantly. Our CG is good, 96.5 to 97 when loaded. When we did the W&B, right side was 15lbs heavier in the rear main. Very little “play” or slack in the system when one is held. 

So...should I adjust the ailerons and rig left up and right down some while the stick is centered? What kind of drag is this causing?

Still can't easily do in-line editing in quoted responses - not fond of this forum software...

Anyway, you don't say if you've got the long or short canard, so it's unclear whether 96.5 - 97" CG is WAY forward in the CG range, or just toward the forward limit. Won't affect the roll issue any, but it's a thing.

You don't say what type of electric trim you have - the original bizarre trim for the VE was an electric trim tab on ONE aileron, run with an RC servo. Is that what you have? Do you have something else?

Did the previous owner/builder fly the plane for 20 years with a severe roll asymmetry? If it used to fly straight, then I'd look VERY carefully at the wing/strake mounting and make sure that everything is exactly correct - there isn't much room to have things be wrong on a VE - if it's wrong, it probably won't go together, but it's something to look at.

15 lb. of weight asymmetry isn't much - was the canopy open when you did the W&B? That would account for much of the asymmetry. So would residual fuel in the tanks, if they weren't completely drained. But it certainly isn't enough to account for the heavy right wing - that's an aerodynamic asymmetry.

You don't say whether the heavy right wing is constant with differing IAS's, or if it gets worse (or better) as you go faster or slower.

The GENERIC answer to this question would be NO, you do not want to re-rig the ailerons to fix a heavy wing - you will lose aileron throw in one direction, and that's a bad idea.

With the understanding that I'm woefully lacking in information here, the right answer would probably be to put a fixed trim tab outboard on the heavy wing - maybe 8" long, 1.5" in chord, 1 - 2 ft. inboard of the winglet, riveted to the TE and at maybe a 20 degree downward deflected angle. Once you fly with that, you can determine if it's too big, too small, needs more or less angle, or wha - you'll need to iterate. If only a small trim tab is necessary to bring the plane into trim, then maybe an integrated gurney flap could be used on the bottom of the right wing, just to be less obtrusive.

[Cmead]

Marc,

thanks for the reply. I’m sorry about the information lacking. I would say this is a project on my hands, but I am leaning a lot on the path.

Long canard and we are middle forward on the CG. POH says 95-101

The trim system attaches to aileron control rod and uses a carbon bow to connect the linear actuator to the rod. So the trim moves both ailerons. The condition is pretty consistent regardless of speed, 110-150 kts it’s constant or very slight. I’ll look closely at the strake to wing, but wings went in pretty smoothly.

Im a newbie to fiberglass. So the trim tab would just rivet on? I would assume with material on top and bottom to “squeeze”on a more significant material? I would definitely talk with my mechanic before, during, after  I’m just trying to understand a little better on the attachment thought. I get the trim tab concept and that sounds like it might be a much better option.

 

 

[Kent Ashton]

It is a common thing to add washers at the wing bolts (in the strake-wing joint) to change the wing incidence.  I suggest that before you add trim tabs.  It is a trial-and-error process, adding and/or subtracting washers at the outboard wing bolts to change the wing incidence and test flying.  This presumes your ailerons are rigged correctly and the winglets are mounted correctly.  If the wing already had washers, it should be noted in the logs.  Perhaps you had some washers a long time ago and they were removed.  

[Marc Zeitlin]

1 hour ago, Kent Ashton said:

It is a common thing to add washers at the wing bolts (in the strake-wing joint) to change the wing incidence...

Perhaps you're not familiar with the Varieze wing attach scheme, but it's completely different than the Long-EZ/COZY/etc. attach scheme and the wing incidence angle is NOT adjustable by any means once the fabrication is complete.

[Marc Zeitlin]

10 hours ago, Cmead said:

The trim system attaches to aileron control rod and uses a carbon bow to connect the linear actuator to the rod. So the trim moves both ailerons. The condition is pretty consistent regardless of speed, 110-150 kts it’s constant or very slight. I’ll look closely at the strake to wing, but wings went in pretty smoothly.

Im a newbie to fiberglass. So the trim tab would just rivet on? I would assume with material on top and bottom to “squeeze”on a more significant material? I would definitely talk with my mechanic before, during, after  I’m just trying to understand a little better on the attachment thought. I get the trim tab concept and that sounds like it might be a much better option.

So you don't have the plans trim system - you've got something more like the LE/COZY/etc. trim systems. When you say that you need to trim for level flight, are you at the full range of trim FORCE, or is the actual aileron DEFLECTION near the full limit to keep the plane level? If the second, I assume that means you can turn VERY well to once side, and almost not at all to the other. Which is it?

In any case, what many folks have done for testing purposes (or permanently, depending upon how lazy one is) is to attach a 1/32" - 1/16" thick AL tab via pop rivets to the trailing edge of the wing outboard where I previously mentioned. If you use baffling rivets, the large head on the top of the TE negates the need for any backing material, and the pulled head of the rivet will be on the AL. One could glass it on as well on the bottom of the TE, with a couple of plies of BID cloth over the TE area and rivets. Belt and suspenders. Start with a BIG tab as making something smaller is always easier than making something bigger. Rigging takes experimentation, and you may need a lot of changes to get it to fly straight. Seeing the plane would help a lot, as it's hard to get a full picture just by vague descriptions.

Some folks, after determining size/shape of a trim tab have actually modified a portion of the TE of the wing outboard of the aileron to have more camber, effectively creating an integrated trim tab. Lots more work...

And if you actually DO have a major roll issue, where you can roll easily in one direction and not much at all in the other, don't fly the plane until it's been at least partially addressed.

[Kent Ashton]

On 7/26/2019 at 9:28 AM, Marc Zeitlin said:

Perhaps you're not familiar with the Varieze wing attach scheme, but it's completely different than the Long-EZ/COZY/etc.

Var-i-eze,  you say?  Never heard of that one.  Must be a new model.

[Jon Matcho]

On 7/25/2019 at 10:11 PM, Marc Zeitlin said:

Still can't easily do in-line editing in quoted responses - not fond of this forum software...

Try this technique, which is exactly what I did to select and reply to your quote in 1.58 seconds. 😉

I welcome any other Questions, Feedback and Suggestions you may have.

[Cmead]

Update.  Added a trim tab about 18" inboard on the right wing.  Worked great.  Wings level and ailerons are exactly even on the TE of the wing.   Now, do those adjust to be both slightly up?  I thought I'd heard/seen that somewhere.  Sorry for all the newbie questions but I am learning.

BTW I did get a set of plans from Terf.  I can't get them to load up on Windows 8 or newer.  Any suggestions on that one????

[Marc Zeitlin]

3 hours ago, Jon Matcho said:

Try this technique,

I vaguely recall you pointing that out to me before.

3 hours ago, Jon Matcho said:

which is exactly what I did

And which I have tried here.

3 hours ago, Jon Matcho said:

to select and reply to your quote in 1.58 seconds.

Eh. Closer to 10 - 15 seconds, by the time you're done with it, but yeah - it works, and I'll try to remember for next time...

Thanks.

[Jon Matcho]

1 hour ago, Cmead said:

BTW I did get a set of plans from Terf.  I can't get them to load up on Windows 8 or newer.  Any suggestions on that one????

Are they still sending CDs?  I'll hook up my CD drive tonight and see what the experience is like.  Knowing how they built it, I'm not surprised it doesn't work.  You should be able to right-click on the drive and then browse the disc instead of running it to get to the files you're looking for.  Once you find the files just copy to your local drive.  I'll check it out as well.