Help! Fixing (strengthening) a crinkled/creased FT Mini Trainer Sport Wing

[cptcorpse]

Hi guys.

After hitting a tree a couple of days ago (don't fly at night lol) I now have a crease in one side of my wing, I thought it would be okay but after trying to fly just now the wing load simply bends it upward and I had to crash land.

The movement of the wing upward is now very easy and it definitely won't fly in its current state.

Are there any common techniques you guys use to repair creased or crinkled foam board? I'm thinking I'll have to add a wooden spar of some kind across the underside of the wing but that won't be easy to fashion and will affect performance.

(PICTURE ATTACHED)

Any help is appreciated.

Thanks.

 

[Ketchup]

You could try cutting a slit in the bottom of the wing and gluing a couple bbq skewers or something in for strength. You could also try just some popsicle sticks glued straight on. There are many ways to fix something like that, and I’m sure that more people will chime in with other ways to do it so you can find the best for your needs. Another option would be to get a sheet of foam and scratch build a brand new wing. It would be lighter and possibly stronger than fixing the new one but it will take more time.

 

[cptcorpse]

Thanks for the reply. Do you have any idea how the plane would perform if I took nearly all of the dihedral out? It would be a lot easier to fix if I could simply glue flat skewers or popsicle sticks to the bottom. I'll probably look at rebuilding the wing as a long-term solution though.

 

[Ketchup]

Thanks for the reply. Do you have any idea how the plane would perform if I took nearly all of the dihedral out? It would be a lot easier to fix if I could simply glue flat skewers or popsicle sticks to the bottom. I'll probably look at rebuilding the wing as a long-term solution though.

If you removed dihedral you would lose some roll stability. It would probably take way more work to do that rather than just fixing it normally though. Since the damage seems to be a couple inches out from the center of the wing you shouldn’t need to remove dihedral to repair it.

 

[cptcorpse]

The dihedral on these wings comes from the center unfortunately which is why this is problematic to fix. I either find a way to fix the broken side to the center with a bracket angled at the correct dihedral or I glue flat skewers or popsicle sticks from the center and past the crease line. The second option would remove some if not all dihedral and the first would require a material that kept its strength when angled.

EDIT: Or I could try glueing multiple short popsicle sticks from the centre over the crease which would keep the dihedral but wouldn't add much "leveraged" strength. I think this is the best option to try first though.

 

[Ketchup]

The dihedral on these wings comes from the center unfortunately which is why this is problematic to fix. I either find a way to fix the broken side to the center with a bracket angled at the correct dihedral or I glue flat skewers or popsicle sticks from the center and past the crease line. The second option would remove some if not all dihedral and the first would require a material that kept its strength when angled.

EDIT: Or I could try glueing multiple short popsicle sticks from the centre over the crease which would keep the dihedral but wouldn't add much "leveraged" strength. I think this is the best option to try first though.

You don’t need to do any of the first options. The last one is good though since the damage is far enough from the center to fix it with shorter sticks that don’t reach the center. I would suggest gluing in a couple popsicle sticks and testing it. Usually they work for me since popsicle sticks are actually kinda strong and the tiny trainer is a lighter plane. If that doesn’t work then you may want to consider a new wing.

 

[cptcorpse]

You don’t need to do any of the first options. The last one is good though since the damage is far enough from the center to fix it with shorter sticks that don’t reach the center. I would suggest gluing in a couple popsicle sticks and testing it. Usually, they work for me since popsicle sticks are actually kinda strong and the tiny trainer is a lighter plane. If that doesn’t work then you may want to consider a new wing.

Yeah, you're right, I was thinking I'd need to strengthen it past the centerline in order to get enough strength but I can just use multiple sticks from the center outward.

Thanks for the help.

 

[BayDesigns]

The strategy recommended above will work but if I were you and I had the time and materials, I would just rebuild the wing- a repaired wing will almost certainly fly just fine but you can only repair a wing so many times. Also, consider the added weight of the stiffener that you use- make sure you do a good weight and balance check. Ketchup knows more than I do, but if I were I. Your position I would just rebuild the wing- it’s foam board, so it’s inexpensive- just one of the many great things about FT planes!

 

[cptcorpse]

The strategy recommended above will work but if I were you and I had the time and materials, I would just rebuild the wing- a repaired wing will almost certainly fly just fine but you can only repair a wing so many times. Also, consider the added weight of the stiffener that you use- make sure you do a good weight and balance check. Ketchup knows more than I do, but if I were I. Your position I would just rebuild the wing- it’s foam board, so it’s inexpensive- just one of the many great things about FT planes!

I agree, my long-term solution is definitely to rebuild the wing, however, I'll repair it for now, not just so I can fly but so I can learn methods of repairing and strengthening which I'm sure will help further down the line.

 

[BayDesigns]

That’s a good idea- hadn’t really thought about the learning benefits.