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Parachute and Shock Cord Protection

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gary7

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I want to provide the best heat protection for my shock cord and parachute as possible. I have a 4 inch BT with a nylon chute for which I purchased a 12 x 12 in nomex blanket. Please tell me exactly how to "cover" the chute and cord with the blanket. Also, if I use other than Kevlar, how do I protect the cord as well? I am aware of nomex shock cord protectors, but that will only cover the first couple of feet. What about the rest of it? I am afraid that if I try to protect the chute and cord too well, I'll end up preventing deployment.
 

ScrapDaddy

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Well for the cord problem Commonwealth displays sells a 60" version of the cord protectors
 

GrossApproximator

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What size motors are you using? For some of my larger rockets (they're lower end "mid power" rockets) I like to attach a piece of nylon strap (long enough to extend outside the rocket at deployment) to my motor mount with epoxy. I then tie (or glue) a loop into the nylon. Finally, I attach my nomex to the loop with a quick link and tie my main elastic shock cord to the loop. This way, the nomex is below the elastic and parachute. What's more, the nomex is easy to transfer between rockets, and I just keep a few pieces of nomex and a few quick links in my rocket box (just my way of saving a few dollars). Of course, the nylon strap would still be exposed to your ejection charge, but it won't be easily damaged. That's my :2:
 

321

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I want to provide the best heat protection for my shock cord and parachute as possible.
I am just now getting back into this but I seem to remember seeing steel braided shock cord thats more like string than steel. You loose the shock absorbing but gain a fireproof alternative.
 

n5wd

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I want to provide the best heat protection for my shock cord and parachute as possible. I have a 4 inch BT with a nylon chute for which I purchased a 12 x 12 in nomex blanket. ... I am afraid that if I try to protect the chute and cord too well, I'll end up preventing deployment.
Gary,

I'm surprised that no one has mentioned another alternative, a deployment bag made out of Kevlar. Using one, you absolutely protect the chute and most of the shock cord from exposure to any hot gasses and particles until after the rocket is apart, and the chute is pulled out of the deployment bag. We're using that method on our NASA-Student Launch Initiative rocket (96 inches tall, 4-inch diameter Blue Tube 2.0) to protect the 72-inch K&S custom chute (over $100), and it works like a champ.

Though you don't get a good look at the deployment itself in the videos, you can see what it looks like at the beginning of the deployment bag having the chute pulled out on our web site: www.texanengineering.org
 
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kandsrockets

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Gary,

I'm surprised that no one has mentioned another alternative, a deployment bag made out of Kevlar. Using one, you absolutely protect the chute and most of the shock cord from exposure to any hot gasses and particles until after the rocket is apart, and the chute is pulled out of the depployment bag. We're using that method on our NASA-Student Launch Initiative rocket (96 inches tall, 4-inch diameter Blue Tube 2.0) to protect the 72-inch K&S custom chute (over $100), and it works like a champ.

Though you don't get a good look at the deployment itself in the videos, you can see what it looks like at the beginning of the deployment bag having the chute pulled out on our web site: www.texanengineering.org
Wayne you beat me to it. A nomex deployment bag is all I use on 4" or larger rockets. I have bags that have over 50 deployments on them and have never had a chute burnt or the cord since I pack everything into the bag.
 
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