Soft Links/Soft Shackle Source

[Emsley]

Not sure where to post this. I've been searching for kevlar soft links. Only one vendor advertises them and they don't seem to want to send anything.

Is it possible to make them? Does anyone have a reliable vendor? I was trying to switch over for a launch next weekend, any direction would be appreciated.

 

[kjhambrick]

@Emsley --

West Marine stocks a few at their Austin ( Research Blvd ) Store and online: West Marine Online - Soft Shackles

EDIT: I see you mentioned Kevlar Soft Shackles. West Marine carries Dyneema Soft Shackles.

Watching this thread ... I would prefer Kevlar too !

HTH

-- kjh

P.S. They're not too hard to make, especially the ones with the double-overhand knots ...

 

[David_Stack]

These folks have recently added kevlar soft links to their catalog of offerings:

https://www.rocketryforum.com/threads/valkyrie-recovery-systems-inc.183009/

 

[spigalau]

These folks have recently added kevlar soft links to their catalog of offerings:

https://www.rocketryforum.com/threads/valkyrie-recovery-systems-inc.183009/

100% on the Valkyrie...

The front is the small, the back is the medium. Both are same length. The more loops you do, the stronger the link becomes.

 

[Emsley]

These folks have recently added kevlar soft links to their catalog of offerings:

https://www.rocketryforum.com/threads/valkyrie-recovery-systems-inc.183009/

Thank you. Says out of stock but I will wait. After reading through other posts here the other ones aren't coming.

 

[Emsley]

Quick update... Valkyrie does have them in a double pack. the single pack is the one that hows sold out. thanks again everyone.

 

[sriegel]

I have some on hand as well. How many did you need?

1000 lb Kevlar, single or double loop lengths (single loop shown). $10/12 respectively.

Steve
Front Range Rocket Recovery

 

[Emsley]

I have some on hand as well. How many did you need?

1000 lb Kevlar, single or double loop lengths (single loop shown). $10/12 respectively.

Steve
Front Range Rocket Recovery

View attachment 634943View attachment 634944View attachment 634945

Thank you srigel. I placed the order but I will spread the love next time. Someone needs to buy the google adwords for these becuase no matter how hard you search only rocketman comes up.

 

[teepot]

This might be a dumb question. Why would you want a soft link? I've never heard of them before.

 

[OZRoc]

Rocketman has these as well.
Cheers, Mark

 

[Emsley]

This might be a dumb question. Why would you want a soft link? I've never heard of them before.

Fits better in a particular booster I built and won't bang around. Lighter but doesn't really matter on this one.

 

[Tractionengines]

This might be a dumb question. Why would you want a soft link? I've never heard of them before.

Size, Weight savings, and flexibility vs a quick link.

WATCH ratings though. Quick links are usually WLL (working load limit). Soft links tell you any one of a number of ratngs...what material its made from, a breaking strength, WLL, etc. )

Quality 1/8 quick link with a WLL rating of ~300# (280-330 depending on manufacturer and material)
Size 1.45"x.75"x.30".
Weight 8.3 grams.

Soft link I made from 750# splicable Kevlar (Emma Kites).
Size .37" ball.
Weight 1.2grams

 

[kjhambrick]

What @Tractionengines said ...

I've also noticed, depending on where I locate a steel quick link on my drogue harness, they can ding my paint too.

-- kjh

EDIT: oops ! @Emsley already said that !

 

[spigalau]

The specs on the VRS softlinks.


5 passes of the small gives you around a 2-3" circle/loop size.

And reason 42 for 'why use softlink ?'
Nothing easier to undo when in the field doing the recovery. Disassembly in seconds, not minutes

 

[teepot]

Thanks. I learned something.

 

[BMcD]

If there is a general aviation airport nearby with skydiving, parachute riggers make soft links all the time. You might have to bring them the kevlar, since flame resistance is not a big concern in sport skydiving, but they will know how to make the links.

 

[Emsley]

Valkyrie did a great job getting the links and some other things to me in 4 days. I do think the 4000+lb shock cord is a bit, well, overkill. I think this is rigged correctly? Doesn't feel like it's going anywhere.

 

[spigalau]

The tab should be rotate 90 degrees so that it runs down the line of the loop.

 

[JLP1]

I got mine from Teddy over at One Bad Hawk

 

[kjhambrick]

<<snip>>
Soft link I made from 750# splicable Kevlar (Emma Kites).
Size .37" ball.
Weight 1.2grams
<<snip piic>>

@Tractionengines --

I looked closely at your knot:

This appears to be an overhand knot ala Stronger Soft Shackle (Mk2)

I tried this one after I gave up on the traditional Button Knot Soft Shackle.

Very NICE !

I was able to make one of these last fall after reading about soft shackles here but I never really trusted MY knot ( it didn't look as tight as yours ).

One Q: How long was your original length of 750# / 2.3 mm Kevlar ?

Thanks !

-- kjh

 

[Tractionengines]

One Q: How long was your original length of 750# / 2.3 mm Kevlar ?

Details in this post/thread. Post in thread 'Finger Trap Technique' https://www.rocketryforum.com/threads/finger-trap-technique.137003/post-2503904

TL : DR... 18" length, tied, proof loaded to 200+ lbs to seat and tighten. Later used to test a 507# rated swivel. (the swivel failed at 526#) To get a tight knot you need to load the brummel splices to seat them, also the overhand knot, before the final "pull through". The slipperyness of the kevlar makes it hard to keep it tight while working. But once it is, it will only get tighter with use.

 

[kjhambrick]

Details in this post/thread. Post in thread 'Finger Trap Technique' https://www.rocketryforum.com/threads/finger-trap-technique.137003/post-2503904

TL : DR... 18" length, tied, proof loaded to 200+ lbs to seat and tighten. Later used to test a 507# rated swivel. (the swivel failed at 526#) To get a tight knot you need to load the brummel splices to seat them, also the overhand knot, before the final "pull through". The slipperyness of the kevlar makes it hard to keep it tight while working. But once it is, it will only get tighter with use.

Thanks @Tractionengines !

It was the thread you referenced here that got me trying to make soft shackles !

EDIT: my looseness was at the base of the overhand knots. I never flew the soft shackle I made but more to come !

Thanks again for the info !

-- kjh

 

[kjhambrick]

Thank you srigel. I placed the order but I will spread the love next time. Someone needs to buy the google adwords for these becuase no matter how hard you search only rocketman comes up.

As @Emsley said, to spread the love a little ...

I ordered four soft shackles from Steve at Front Range Rocket Recovery via his Contact Steve at FR3 Page on Tuesday and they arrived Friday.

See @sriegle's Post #7 above

They're just as beautiful in person as they were in Steve's Post !

Especially the Button Knots and the consistently close, nicely tapered buries inside the loops of the four soft shackles:

The brummel splices close up nice and secure and I've got no reservations about flying these at all !

I'll be flying two of these next time I launch ( one on the drogue-end and one on the main-end ).

I'll report if there are any issues but I expect they'll work great !

Thanks to Steve and to everyone here for reminding me to get back on the soft shackle train !

-- kjh

p.s. Now that I can see a Button Knot first hand, I MAY try making another soft shackle with 2.3mm / 750 lb braided Kevlar but then again maybe knot

 

[Tractionengines]

I MAY try making another soft shackle with 2.3mm / 750 lb braided Kevlar but then again maybe knot

It's all about practice...with any splicing technique. 18" of 750# kevlar is not much cost. Even if it takes a few tries. Neatness counts, a lot. Take your time. Go one step at a time. And make some notes. (Original length, exactly how much taper, how long the bury, etc.)

Just make a bunch. You'll get better quickly. Use the ones less well formed in less critical locations.

 

[kjhambrick]

One thing I believe I need to do if I want to do more than simple loops in the ends of my braided Kevlar shock cords is to 'invest' in a decent set of fids.

I've been using bare copper wire from a 36-inch electric match and a Pentel mechanical pencil tip to manipulate the braided Kevlar

These work OK for making a brummel splice and pulling a buried pre-tapered tail but they're not too useful for much else ...

 

[Tractionengines]

I don't think you'll find official finds for the small sizes. The smallest I have will fit "some" 1/8 hollow braid. But not all; and not the 750# / 1000# Emma kits kevlar. To get it to go you have to upen the weave too much and takes a lot of time.

Some "big" sewing needles from Michael's or Hobby Lobby will work fine. Just dull and smooth off the point. A big eye will hold the end of the taper. (I'll get a photo of the one I use on 750# later.) Works well on the LOC 3/16" tubular nylon too.

Edit to add:
But YES, For anything bigger a GOOD fid set is worth it. By good I mean: Nice smooth edges. A polished surface. And correctly sized "catch" on the ID to hold the material in.

A "cheap" set may have edges which cut strands. Any roughness is more friction when your trying to burry 72 diameters deep. And if the catch lets go of material 1/2 way you need to pull it back out and start over.

 

[John Kemker]

This thread has been giving me ideas about making soft shackles with some Kevlar "thread" (not really thread, but really small woven Kevlar) for LPR.

 

[Tractionengines]

This thread has been giving me ideas about making soft shackles with some Kevlar "thread" (not really thread, but really small woven Kevlar) for LPR.

FYI.. If you want to experiment with it.
I have done splices & soft shackles in the 3 sizes that Emma Kites lists as "splicable" (550, 700, & 1000#). I have also done it with LOC Precision 1/8" & 1/4" flat braided Kevlar & 3/16" tubular nylon.

 

[John Kemker]

FYI.. If you want to experiment with it.
I have done splices & soft shackles in the 3 sizes that Emma Kites lists as "splicable" (550, 700, & 1000#). I have also done it with LOC Precision 1/8" & 1/4" flat braided Kevlar & 3/16" tubular nylon.

I'm not sure what size Kevlar this is. I'll have to measure it.

 

[Tractionengines]

Here is what I use to work with these sizes of materials. Kevlar scissors. Then the larger needle mostly, with the shorter one for detail work.


Big needle is 5" long x .075" diameter. The eye is .050" x .625". I did dull off the point, and then smoothed each end with needle files, and emery cloth. Then a little polishing with a scotch-bright pad. It works well for the 500, 700, 1000# kevlar. You can work it thru point first and then pull the tails. OR work it back thru the material eye first.

What your looking for is a long shank, then a long narrow eye. If the eye bulges out too big it's to much friction or will loose the tread. If the shank is not long enough, its hard to hold onto. And harder to get the 40-50x diameter Barry length.