Mid Power (D,E,F):Too many swivels?

Jacktango22

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How common a practice is it to have a swivel for the shock cord to nose cone connection and a separate swivel to attach parachute cord (either on the nose cone itself or a bit lower on the shock cord)?

All thoughts appreciated.
 

waltr

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At most I use one swivel on the cord between the body, on the short Kevlar to the anchor, and the long cord to the chute & nose.
 

T-Rex

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The only swivel I ever use is between the 'chute and the shock cord. I use very large snap swivels from the saltwater fishing section.

YMMV
 

bjphoenix

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(I thought mid-power was E, F, G.)

I have not used swivels in the past for F & G. These days I do use a lot of swivels for D- I have interchangeable parachutes and shock cords so that means 1 swivel on the parachute and one each end of the shock cord. For my F and G rockets I'm going to add swivels to them too, now that I know there are large swivels available for fishing. However I'm not sure I've seen evidence with my rockets that it makes much difference to anything.
 

teepot

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I use Dr Fish stainless steel
How common a practice is it to have a swivel for the shock cord to nose cone connection and a separate swivel to attach parachute cord (either on the nose cone itself or a bit lower on the shock cord)?

All thoughts appreciated.
swivels. One from the shock cord to the nose cone and one from the shroud lines to the shock cord. My chutes move from rocket to rocket. The chute swivel is already attached. Then a quick link on a loop in the shock cord. Chute swivel to the quick link.
 

Jacktango22

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Thanks for input. I want to be able to switch out nose cones (add one with payload for example) and same with chutes. Going to test some concepts at club launch in Connecticut this weekend.
 

lakeroadster

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Thanks for input. I want to be able to switch out nose cones (add one with payload for example) and same with chutes. Going to test some concepts at club launch in Connecticut this weekend.

More than one is to many IMO, and as far as location, six of one, half a dozen of the other. I put a Barrel Swivel on the shroud lines of the parachute so I can swap out parachutes.
 

Handeman

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Most of you at talking about "snap swivels" so you can change things out. That means you are using the "snap" part. Is the "swivel" part actually needed?

I seldom fly MPR, but I do like @waltr on all of my HPR. The swivel (no snap part) is attached to the booster/fin can only, the shock cord, chute, payload/nose cone don't have any swivels at all. Quick links are used if things need to be swapped out.
 

techrat

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As I tend to re-use parachutes between models (at a typical launch I may bring 7 rockets, but only 4 chutes); snap swivels are a necessity, but on some of my larger rockets (anything BT-70 and up), there may be a separate swivel between the nosecone and shock cord. But not always. But I experiment and use small carabiners as well, which allow me to swap chutes quickly and easily.
 

DigBaddy

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At least one inline in the shock cord. One on the chute (snap swivel) won't hurt. As for why one inline on the shock cord, watch my Nike-X drop before the chute release opens.

 

Handeman

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At least one inline in the shock cord. One on the chute (snap swivel) won't hurt. As for why one inline on the shock cord, watch my Nike-X drop before the chute release opens.

That seems pretty common for DD flights. I had one rocket where the fin can would spin +100 RPM on the way down under drogue. I had a ball bearing swivel attached to the fin can so the shock cord never twisted up. It stopped spinning as soon as the main deployed. I guess the JLCR works a lot like a drogue on a DD flight and the fin can can start spinning pretty quick. A swivel near the fin can is certainly a good idea.
 

waltr

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That seems pretty common for DD flights. I had one rocket where the fin can would spin +100 RPM on the way down under drogue. I had a ball bearing swivel attached to the fin can so the shock cord never twisted up. It stopped spinning as soon as the main deployed. I guess the JLCR works a lot like a drogue on a DD flight and the fin can can start spinning pretty quick. A swivel near the fin can is certainly a good idea.
Exactly my experience, Under drogue the fin can spins really fast and without a good swivel the cord is very twisted.

As I tend to re-use parachutes between models (at a typical launch I may bring 7 rockets, but only 4 chutes); snap swivels are a necessity,

For smaller rocket I use the a snap swivel for chute but not on Mid-power (>600gram) and up.
For these I tie a loop in the shock cord a foot or two down from the nose. Then it is very easy to pass the chute shroud lines through the loop and the chute through the shroud line loop. Quick easy attachment of chute without any extra part to fail. Also does not depend on the nose attachment to bring rocket down safely.
 

David Schwantz

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Best place for a swivel, on any size rocket, is from the fin can to the shock cord. The fin can is what will mainly twist, due to it has fins to catch the wind.
 

DirkTheDaring

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Heck, even my swivels have swivels. Not uncommon for me to have 3 or more snap swivels. Why not? The weight is trivial, though I’m not aiming for records, and it makes it super easy to untangle things and swap parts. I’ve had exactly one swivel failure with a poorly time ejection.
 
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