Wing Bolts vibrating loose
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Wing Bolts vibrating loose
I landed my nitro Sig Kougar today and one of the wing bolts had vibrated loose. It seemed snug enough going it. It must have been just the right resonance. Does anyone know something sticky I could put on them to avoid this? Maybe a little foam glue? Thanks
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I put epoxy in it a couple times and threaded in the bolt. I think maybe it's more snug now.. I think I'll put this one on slightly tighter than the other one so it takes more of the load. I will try it again on Monday and keep a closer eye on it. Thanks
#9
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This has me wondering just how loose the threads are. I have waxed up a nylon bolt and applied some epoxy laminating resin with some milled fiber added in to the hole in order to fix the same issue. In my case the molded threads worked just fine because the epoxy had a fibers added to it. The suggestion of CA was a good one as it would have penitrated the wood some and helped reduce the hole diameter some. Straight hobby type epoxy is really fairly weak stuff. If your threads are more epoxy then wood you could be setting yourself up for a failure.
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The bolts went in tight enough that I was surprised it vibrated out. A coating of epoxy has made them even tighter though. I'll keep a closer eye on them. I'm going to fly it again on Monday. What is milled fiber?
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I've never heard of a nylon bolt vibrating loose. That's the whole point of using them.
I'd be concerned that it actually pulled out of worn threads. It's practically impossible for it to have vibrated loose if the threads were a little tight and you tightened it enough to have some stretch.
I'd be concerned that it actually pulled out of worn threads. It's practically impossible for it to have vibrated loose if the threads were a little tight and you tightened it enough to have some stretch.
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I've never seen it before either. But with other one holding the wing solid, it was definitely backed out not pulled out. A little bit of epoxy on the threads has it staying in place now. Perhaps the threads aren't as good as new. but I can tell they are still in decent shape by the amount of torque I'm able to tighten them to without them slipping.
Last edited by douglas racer; 05-19-2021 at 09:11 AM.
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I put new bolts in. But I think a little epoxy on the wood is what fixed it. It definitely backed out though. I've been flying it four days in a row now and it's holding good.