Estes' new Aramid shock cord

[Huxter]

So is Aramid the same thing as Kevlar? Is Aramid superior to braided Kevlar?

ACP composite lists Aramid cord as:
"An eight strand, tightly woven braided cord manufactured from high strength KEVLAR® 29 fibers"
https://store.acpcomposites.com/braided-aramid-cord

It looks pretty common in climbing circles?

See if this link works:
https://estesrockets.com/products/aramid-cord?utm_source=Klaviyo&utm_medium=campaign&utm_campaign=Email 1 - Aramid Cord&_kx=MjOwjhALsSuNs0pSE92D_BlnhUckQRtwWPllNxggEfY.WF3xvM

 

[tsmith1315]

Kevlar is a brand name of aramid products.

 

[Art Upton]

I use those all the time.

 

[Handeman]

So is Aramid the same thing as Kevlar? Is Aramid superior to braided Kevlar?

ACP composite lists Aramid cord as:
"An eight strand, tightly woven braided cord manufactured from high strength KEVLAR® 29 fibers"
https://store.acpcomposites.com/braided-aramid-cord

Actually the other way around. KEVLAR® is a brand name that uses aramid fibers in their products.

 

[SolarYellow]

I buy most of my aramid cord AliExpress. It's much cheaper than anywhere else. Especially that Estes pricing. Second choice is Amazon.

Except CS Rocketry had its mule tape sale awhile back. That was awesome!

 

[Initiator001]

The real question is what is Estes doing with Aramid/Kevlar line?
Will there be future kits/products which use this material?

 

[lr64]

I guess if you pick something as stiff as Kevlar, you will certainly cause a shock when it pulls up tight, causing a high load and more stress on everything. A stretchy shock cord can be much weaker and still adequate. And gentler on the rest of the rocket. Perhaps I'm missing something?

Estes used to provide rubber strip in some of their kits. Very stretchy stuff, though it breaks down over long periods of time or many stretches that are near its capacity.

Is there something wrong with nylon?

 

[ep29030]

It’s true that kevlar cords can put high loads on parts when they reach their limit-no stretch like nylon. That is minimized by using a longer cord so it doesn’t max out during deployment. You can also soften the stretch by bundling your cord in rubber bands or a wrap of tape—energy is bled off by breaking the tape/rubber band. Kevlar’s appeal is its size-much smaller/lighter pack than nylon can offer.

The other concern with kevlar is tube zippers—it does a nice job of slicing tubes. But it can be controlled with a small wrap of tape around the kevlar line where it meet the top of the tubing. Or buy the No Zip Strips that NewWay Rocketry sells (get them at eRockets.biz).

 

[cwbullet]

The other concern with kevlar is tube zippers—it does a nice job of slicing tubes. But it can be controlled with a small wrap of tape around the kevlar line where it meet the top of the tubing. Or buy the No Zip Strips that NewWay Rocketry sells (get them at eRockets.biz).

Or add a rubber of sponge ball to cushion the hit.

 

[mh9162013]

Is there something wrong with nylon?

in LPR rockets, yes.

 

[hcmbanjo]

The real question is what is Estes doing with Aramid/Kevlar line?
Will there be future kits/products which use this material?

The recent Black Brant XII had Kevlar line included in the kit.
https://modelrocketbuilding.blogspot.com/2023/09/estes-black-brant-xii-kit-9723-build_16.html
Estes might be including Kevlar in some of their new larger kits.

 

[DAllen]

Body tube zipper enters the chat

 

[n3tjm]

My concerns about using kevlar:

Damage to the edge of the tube, Zippers. Harder to insert into smaller tubes. More stress. More lightly to tangle. Stress can be alieviated by making it longer but that makes it harder to insert into the tube and increases chance of entanglement. Antizipper methods can also result in entanglements. I had several models crash because the recovery got snagged with the antiziper.

With smaller rockets that come with kevlar shock cords, I usually "upgrade" them to the "Estes" style tryfold shock cord mount. Worked for decades, usually outlasts the rocket, and easy to replace if needed, which is rare. Larger rockets I usually use tubular or strap kevlar or nylon, and the anti-zipper may be as simple as a ball, or a kevlar band around the edge of the tube.

 

[Capt. Eric]

Is there something wrong with nylon?

It melts and gets cut much easier. I used one that came with my PML Bull Pup 2.2 and it cut on its first flight. Thankfully it is a rugged rocket and survived, but I won't use small nylon ever again. Not when Kevlar is so much better, and not too expensive these days.

 

[dhbarr]

For a lot of my cardbirds, I just use Kevlar for the lower portion and retain the elastic on the upper portion. Tape up the joint with some flexible medical tape, acts as anti-zip and allows replacement of the rubber.

 

[4regt4]

The real question is what is Estes doing with Aramid/Kevlar line?
Will there be future kits/products which use this material?

Maybe when they placed their order from Emma's Kites on Amazon they fat fingered the quantity and are trying to dump the excess....

Hans.

 

[SolarYellow]

Maybe they did like CS Rocketry and bought a drum-sized spool of it in China to get the cost down as far as possible, and are now trying to dump the excess.