Swapping rubber band shock cord for elastic.

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ascastil

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Im going to go hunt down some elastic from somewhere, fabric or hobby store. Should I just get the same length and width as the rubber one, or maybe a little longer?
 

les

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Longer - generally the supplied cords with a typical kit are too short. Try doubling the length
 

ascastil

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Ok thanks. I went ahead and mounted kevlar 3x length of bt. On top of that double the kits shock cord. Elastic is ok?
 

rharshberger

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Ok thanks. I went ahead and mounted kevlar 3x length of bt. On top of that double the kits shock cord. Elastic is ok?
Kevlar, definitely a better choice. I personally no longer use elastic or rubber band materials in my rockets, they all get long kevlar or nylon shock cords.
 

ascastil

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Kevlar and elastic sound ok to use on an Estes STM 012? Id like to use AT E roloadables on it. Just trying out some basic upgrades I guess you could say.
 

dhbarr

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Should work great. I personally like kevlar up to the top of the tube, then attach the original cord. Any concerns about the weight of all that additional cable sliding aft under boost?
 

ascastil

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I can cut it shorter if necessary. I just saw it mentioned in an Apogee video to use 3x length of bt. Should i shorten it?
 

dhbarr

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I can cut it shorter if necessary. I just saw it mentioned in an Apogee video to use 3x length of bt. Should i shorten it?
Only you can answer that question, but it does need to be at least three times the length of the the longest your canopy can be.

I'd say do what seems right all the way to flight-ready-sans-igniter. Measure CG with the laundry as far forward as it can go, then again with as far aft as it can slide.
 

TangoJuliet

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If you're doing Kevlar and then elastic, keep the Kevlar shorter that the body tube to reduce the risk of a zipper.
 

Cabernut

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If you go full kevlar, keep it really long. I have an LPR that ripped a 1/8" ply CR upon eject because the kevlar cord was just about 3.5 feet. I lengthened it to 8 feet and it works just fine now. Good thing about thin kevlar cord is that it packs small.
 
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