Kevlar Shock Cord Questions

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Woody's Workshop

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I'm building a BT-80 Wizard with 29mm Engine Mount and I purchased 140 lb Kevlar for the shock cord. This is my first time using kevlar and my question is do you still use elastic a the chute end to absorb the initial sudden decrease in speed upon deployment? I will be using a nylon chute if that makes a difference, and a nomex blanket. I always use snap swivels so changing things is fast and easy.
So at the end of the kevlar I was going to tie a 3 way swivel, chute, blanket & kevlar. Is this a good idea? Or should I just tie a loop in the end of the kevlar. Not concerned with weight at all.
I was going to mount it to the top centering ring on the engine mount, but I decided to put a baffle in it, so I believe the kevlar would then me mounted to the top of the baffle as well?
Thank you kindly in advance.
 
I'm building a BT-80 Wizard with 29mm Engine Mount and I purchased 140 lb Kevlar for the shock cord. This is my first time using kevlar and my question is do you still use elastic a the chute end to absorb the initial sudden decrease in speed upon deployment? I will be using a nylon chute if that makes a difference, and a nomex blanket. I always use snap swivels so changing things is fast and easy.
So at the end of the kevlar I was going to tie a 3 way swivel, chute, blanket & kevlar. Is this a good idea? Or should I just tie a loop in the end of the kevlar. Not concerned with weight at all.
I was going to mount it to the top centering ring on the engine mount, but I decided to put a baffle in it, so I believe the kevlar would then me mounted to the top of the baffle as well?
Thank you kindly in advance.

I would use the elastic. Sudden shocks are not a good thing.
The rest of your plan is good. :)
 
Woody:
Never used a 3-way swivel but do indeed use 1/4" and Up elastic above the Kevlar to ensure the Nose section has time to slow before hitting the end of the stretch. Generally 36 to 60" is more then enough along with 3 feet or so of kevlar beyond the forward end of the model.

If the 3-way swivel is of good quality it'll probly be a good thing to hold the nomex blanket.
Personally I just tie a butterfly knot where I what the blanket to attact. The knot is easily removed for adjustments if needed even after long periods and many ejections:) It's an easy knot to master and very useful on all size rockets.

ButterFly Knot_4pic tutorial pg_07-20-05.jpg
 
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