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Old Jul 07, 2013, 01:38 PM
I land when i CFIT!
flytrip's Avatar
USA, UT, Sandy
Joined May 2007
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Jw Spar repair

Hey Folks,

I have a light Jw (53oz) that has a broken spar, about 8" from the wingtip.
Feels like a pretty clean break, rest of plane is still in good shape.

Looking for ideas on how to fix the spar without dismantling the whole thing and cutting out the whole spar. If that's the case, I'd rather just buy a new one.

TIA,

Colby
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Old Jul 07, 2013, 04:26 PM
gizzo don't tweet
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Adelaide, Australia
Joined Jan 2008
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I've "fixed" loads of broken spars in foamies. I do it like this: Cut away a strip of covering alongside the spar broken part, the width of a new spar. Dremel out a channel to take a new piece of spar. Glue the new piece in, finish nicely, recover with tape or something. If you broke top and bottom ones, do it twice. The length of the new piece you'll have to decide for yourself. If its a break in the centre of the wing, Id use about 12", out near the tip 5" or 6" will be plenty. My foamies end up riddled with these kind of repairs and the still fly fine. Just keep getting heavier.
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Old Jul 12, 2013, 03:27 AM
DS state of origin NSW Vs QLD
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Originally Posted by gizzo View Post
Just keep getting heavier.
And flying faster
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Old Jul 12, 2013, 11:16 PM
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USA
Joined Sep 2008
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I will add to Gizzo's repair tip to double check the tip-to-tip balance of the wing after the repair. It will most likely be off quite a bit so its a good time to balance things out again after major surgery like this.
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Old Jul 13, 2013, 05:12 PM
I land when i CFIT!
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Thanks fellas, got it fixed.
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Old Jul 14, 2013, 04:34 PM
chronic in training
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L.A. beautiful san fernando valley
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wouldn' t the spar just break again where the new piece...

Quote:
Originally Posted by gizzo View Post
I've "fixed" loads of broken spars in foamies. I do it like this: Cut away a strip of covering alongside the spar broken part, the width of a new spar. Dremel out a channel to take a new piece of spar. Glue the new piece in, finish nicely, recover with tape or something. If you broke top and bottom ones, do it twice. The length of the new piece you'll have to decide for yourself. If its a break in the centre of the wing, Id use about 12", out near the tip 5" or 6" will be plenty. My foamies end up riddled with these kind of repairs and the still fly fine. Just keep getting heavier.
hits the old spar due to wing loading? or am I missing something?

thanks
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Old Jul 15, 2013, 11:55 PM
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Quote:
Originally Posted by gizzo View Post
I've "fixed" loads of broken spars in foamies. I do it like this: Cut away a strip of covering alongside the spar broken part, the width of a new spar. Dremel out a channel to take a new piece of spar. Glue the new piece in, finish nicely, recover with tape or something. If you broke top and bottom ones, do it twice. The length of the new piece you'll have to decide for yourself. If its a break in the centre of the wing, Id use about 12", out near the tip 5" or 6" will be plenty. My foamies end up riddled with these kind of repairs and the still fly fine. Just keep getting heavier.
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Originally Posted by grfcon View Post
Wouldn' t the spar just break again where the new piece hits the old spar due to wing loading? or am I missing something?

thanks
Grfcon, I read Gizzo's post as meaning adding a new section of spar alongside the broken original spar; with the new section acting as a doubler. Ideally, the doubler would taper in thickness at its ends to reduce the chance of a stress concentration.
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Old Jul 16, 2013, 11:07 AM
chronic in training
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L.A. beautiful san fernando valley
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Originally Posted by DT56 View Post
Grfcon, I read Gizzo's post as meaning adding a new section of spar alongside the broken original spar; with the new section acting as a doubler. Ideally, the doubler would taper in thickness at its ends to reduce the chance of a stress concentration.
I see it now..didn't catch that the first time. makes sense..thanks for pointing it out.
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