FT Tutor uncontrollable roll

[Foamforce]

Maybe his horizontal stabilizer was installed warped? I don't it would cause that much of a problem though....

A warped horizontal stabilizer wouldn’t cause this much left roll, it‘s probably the wing itself that is warped. Left tip up, right tip down. When the wing is warped even a little bit, it’s like having a lot of aileron in that direction, because the entire wing is acting as a giant aileron.

Although I take back what I said about the thrust angle. It should be to the right, but it appears to be a little to the left, so that probably contributes somewhat, though likely not the main problem. If it got worse after a crash, that’s because the foam on the left side of the power pod got mushed in a little. Pinch the mushed part of the foam pretty hard while pulling the firewall to the other side and you can adjust it enough. By the way, you can test if it’s a thrust angle issue by turning off the motor and gliding without it for a few seconds. If the left roll goes away, then it was a thrust angle issue.

 

[Houndpup Rc]

A warped horizontal stabilizer wouldn’t cause this much left roll, it‘s probably the wing itself that is warped. Left tip up, right tip down. When the wing is warped even a little bit, it’s like having a lot of aileron in that direction, because the entire wing is acting as a giant aileron.

Although I take back what I said about the thrust angle. It should be to the right, but it appears to be a little to the left, so that probably contributes somewhat, though likely not the main problem. If it got worse after a crash, that’s because the foam on the left side of the power pod got mushed in a little. Pinch the mushed part of the foam pretty hard while pulling the firewall to the other side and you can adjust it enough. By the way, you can test if it’s a thrust angle issue by turning off the motor and gliding without it for a few seconds. If the left roll goes away, then it was a thrust angle issue.

He said he rebuilt the power pod after the crash...

 

[Houndpup Rc]

He said he rebuilt the power pod after the crash...

Though you are right, it looks like it has some left thrust angle, not that bad and he should be able to tune that out with the rudder.

 

[Houndpup Rc]

Though you are right, it looks like it has some left thrust angle, not that bad and he should be able to tune that out with the rudder.

My power pod in my simple scout is ready to fall out and moves all over the place, but it still flies great! (It's getting near to retirement....)

 

[Merv]

...Could my angle of thrust be an issue... ...Any recommendations...

I doubt it's the thrust angel.
I suspect your wing has a twist.

I always check the wings I build for twist. I take 2 yard sticks and set them on the wing, then look down the wing to see if the stick line up or if one is at a twist to the other. The stick just exaggerate the twist and make it easier to see. I have never built a perfectly straight wing, as long as the twist is less than an 1/2 inch, that’s good enough for me. Woodworkers use this technique to check the flatness a board, they call them winding sticks.

 

[X_that_one_guy]

Hello, I just finished my first scratch build of an FT Tutor. I've got a 1120 kv motor with a 9 X 4.5 prop and a 1550 mah 4s lipo on it, trying to follow the recommed specs. My problem is that when I try to fly it, the plane rolls to the left while I hold full right ailerons. When I originally encountered this issue on my maiden flight, I shifted the wing to the left to move the center of lift to the left. This worked fine, even got it trimmed out, View attachment 248633 View attachment 248634 until I crashed it after flying it in the direction of the sun, lost sight and control. After some minor fixes, including rebuilding the power pod, it still rolls if not worse. The only solution I found was to strap a weight to the right wing, but I'd like to solve the problem in the first View attachment 248635 View attachment 248636 place. I've balanced the wings and fuselage separately on my fingers, and nothing seems to be out of place. Could my angle of thrust be an issue? I built it to the plans? I'm also flying with the recommended CG placement with the battery in place. Any recommendations or fixes would be very much appreciated!

So turns out my wing was warped, I think it was from the very beginning when I built the spars. On one of them, one side was cut a bit taller. I built a new wing, being sure to follow a straight edge as much as I can, now the plane flies beautifully with no issues.

My question now is, is there anything I can do to fix this warped wing?

 

[X_that_one_guy]

I doubt it's the thrust angel.
I suspect your wing has a twist.

I always check the wings I build for twist. I take 2 yard sticks and set them on the wing, then look down the wing to see if the stick line up or if one is at a twist to the other. The stick just exaggerate the twist and make it easier to see. I have never built a perfectly straight wing, as long as the twist is less than an 1/4 inch, that’s good enough for me. Woodworkers use this technique to check the flatness a board, they call them winding sticks.

I'll be sure to use that trick in the future, thank you!

 

[Houndpup Rc]

So turns out my wing was warped, I think it was from the very beginning when I built the spars. On one of them, one side was cut a bit taller. I built a new wing, being sure to follow a straight edge as much as I can, now the plane flies beautifully with no issues.

My question now is, is there anything I can do to fix this warped wing?

Nice! I don't know of anyway of fixing it.....

 

[Foamforce]

So turns out my wing was warped, I think it was from the very beginning when I built the spars. On one of them, one side was cut a bit taller. I built a new wing, being sure to follow a straight edge as much as I can, now the plane flies beautifully with no issues.

My question now is, is there anything I can do to fix this warped wing?

Unless it’s a really huge amount of twist, you can probably trim it out like I said in post 19.

If you don’t mind wrinkles, you can man-handle it and bend it back into shape. That WILL cause cosmetic creases, but will work.

Otherwise, you could just cut it in half and re-glue the two halves back together with a slight pivot to counter the twist. You could get it pretty good like this.

 

[Merv]

...My question now is, is there anything I can do to fix this warped wing?

I theory, yes, but I'm not sure it is worth the effort. Your time is better spent on a new wing.

The twist is introduced when the wing is folded. For a straight wing, make sure the corners of the trailing edges line up. If the top layer is shifting right or left relative to the bottom, you'll have a twisted wing.

I make my initial fold without the spar. I will keep redoing the fold until the corners line up. Only when I'm happy with the fold will I add the spar & finish the build. Paying attention to the corners as I add glue.

 

[oneplaneman]

I seem to have the same issue you state here. Mine is very manageable and fixed with mechanical trim. I notice the right aileron is not flush with the wing, but it flies great now. I built mine from the Tutor bundle, and indeed, my wing is just slightly warped.

 

[Merv]

...Mine is very manageable and fixed with mechanical trim....my wing is just slightly warped.

As I mentioned, none of my builds have been perfect, all have required some trim. But that is the reason for trim, to correct any errors in building.

Your plane sounds completely normal to me.