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ltdiver

Slinks--When should they be replaced?

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With the recent Slink failure with one of our Perris instructors, I did a little search both on the PD site and here on dz.com for when the recommendation for replacing them is.

I didn't find an official word on this.

So, I'm writing this for rigger's advice. I've been told that the theory is to change your Slinks with every new line set. And to, of course, inspect them throughout the course of use for wear and proper positioning.

Is there any more advice out there, from certified riggers, on what is best for the care and maintenance of Slinks?

ltdiver

Don't tell me the sky's the limit when there are footprints on the moon

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Of course for now they've been relying on a standard inspect for wear or damage type of check by riggers for the reserve slinks.

Their website mentions how one of their criteria for the design was that it have no metal parts. I don't understand what is so bad about designs that use a small metal ring (Aerodyne) instead of the tab. Their slink info ridicules that design, as if it would be stupid - implying the primary objective was to remove all metal from the component, which is just silly.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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Under normal conditions would slinks likely have a higher or lower breaking force than a set of mini risers?

Any one care to wager an educated guess? (I know it is a tough question with tons of variables).
"The restraining order says you're only allowed to touch me in freefall"
=P

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Under normal conditions would slinks likely have a higher or lower breaking force than a set of mini risers?

Any one care to wager an educated guess? (I know it is a tough question with tons of variables).



I would expect the slink to be much stronger, I thought that PD's promotional info supports that.

One might suspect that the slink had the tab out of place (not hidden in the riser). I've seen so many people with slinks like that, which is definitely not how it is intended. I've called it to the attention of a few people, but they all just ignore it. I would expect a much lower strength with the slink tab out of position. Of course the investigators will be looking for this and it is is easy to confirm.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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Under normal conditions would slinks likely have a higher or lower breaking force than a set of mini risers?

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

When Parachutes de France introduced their re-usable soft links - at PIA 2005 or 2007 ? - they showed a video of pull testing that showed the stitching (multiple bar tacks) on a mini riser (one inch wide type 17 webbing) consistently failing before the soft link.

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It does not really matter what material you use for the lump on the end of a soft link.

Parachutes de France use steel rings.

Performance Designs uses a little piece of tape, folded and bar-tacked until it is too fat to slip through the loop.

Precision Aerodynamics uses brass rings.

Aerodyne uses stainless steel rings.

Finally, the hillbillies - at Flight concepts and HiPerUSA - just tie a large, ugly stopper knot in the end of their soft links.
Hee!
Hee!

All the different lumps serve the same function.

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I would expect a much lower strength with the slink tab out of position



Could you please explain why you believe this. It was my understanding that one of the benefits of slinks was the fact that unlike rapide links slinks have the same integral strength in any direction.
I like my canopy...


...it lets me down.

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It doesn't matter how worn they are if they are not routed correctly! I have seen riggers pull up rigs that have been jumped where the tab has just been pulled through the loop rather than doubling it over (still going twice through the risers and lines). Not saying thats the case here of course!!

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I would expect a much lower strength with the slink tab out of position



Could you please explain why you believe this. It was my understanding that one of the benefits of slinks was the fact that unlike rapide links slinks have the same integral strength in any direction.



The installation instructions say that leaving the tab out "will result in excessive wear of the Slink, potentially leading to a structural failure."

So, my memory was wrong about it being an issue of strength, at least when first installed. Anyway, the instructions make it very clear which way is right.

http://www.performancedesigns.com/docs/SlinkInstructions_1.pdf

I would rather have the tab tucked away so that nothing can snag the tab during deployment.

It was very easy to get slinks to take a 'good' set with my wide/normal risers. Perhaps it is not so easy with mini risers. I actually took the time to understand a new-to-me component when I got a new rig, so I made sure the slinks were right before the first few pack jobs. Too many don't bother to learn, so the slinks take a bad set and that is hard to change.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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It doesn't matter how worn they are if they are not routed correctly! I have seen riggers pull up rigs that have been jumped where the tab has just been pulled through the loop rather than doubling it over (still going twice through the risers and lines). Not saying thats the case here of course!!



I wonder if such a misrouted Slink is stronger with the tab tucked away correctly than if the tab is exposed. I realize that the strength is not what it should be, just wondering if a properly placed tab (hidden) helps to minimize the effect of a routing error.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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the hillbillies - at Flight concepts and HiPerUSA - just tie a large, ugly stopper knot in the end of their soft links.
Hee!
Hee!



LOL, I thought that was funny when I frst got a set from Beeze and now have a couple of sets. Nice little set up.. I have used a number of the Hyper link sets and they are easy to install and work fine.

I try/plan to change "slink" sets with a canopy reline.. I have heard of people (including myself) going much longer on a older set. I had a really worn home made set about 12 years ago that I had on for 1200 jumps or so. Did not seem to be in bad shape when I took them off either. But that said I guess the cost is miniml to change them every 5-600 jumps compared to others that can happen.. :)
Scott C.
"He who Hesitates Shall Inherit the Earth!"

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That is because the first Slink failure was related to a rough edge - on a slider grommet - chewing on an exposed Slink tab.
Now silly people are perpetuating the story, without the back ground knowledge.
This is how silly urban myths get started.

Soft links are equally strong no matter which way the tab points.

The short term solution to buddy's problem would have been to hand tack the Slink tabs inside the risers.
However, the real solution was to take a piece of fine sandpaper - or emery cloth to his rough slider gormmets.

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I have seen riggers pull up rigs that have been jumped where the tab has just been pulled through the loop rather than doubling it over (still going twice through the risers and lines).

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Sounds like the guilty rigger only read the Parachutes de France instruction sheet and has not learned a damn thing since then.
All subsequent - soft link manufacturers - insist on a lark's head knot/doubling it over.

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All soft links are not created equally.With each soft link manufacturer there are also a set of instructions for the install.Not all instructions are the same for all makes of soft links. The soft link is such an easy puzzle that it's also easy to mess up. For those who read instructions, it is easy to get it right the first time.

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I would rather have the tab tucked away so that nothing can snag the tab during deployment.



You are right.;) Here is my "snag mal story".

I had the Aerodyne style slink. My first rigger who assembled the rig said, "These can be tacked but instead I prefer just aligning them before each jump for a few jumps until they set in and stay in place on their own. That way you can change your canopy without the tack being replaced." (Of course the reserve was tacked)

Well, 3 out of 4 risers set in the right spot, but one (right rear) set just enough out of place that the ring sometimes would come out. Maybe 20 degree rotation. I would after every jump spin it back into place, but it was hopeless without a tack. I never thought it would cause a mal sticking out half way...

Well, twice it caused a mal. (No I am not an idiot, it took two mals for me to see what was wrong because the first was misdiagnosed.)

Both times the brake line wrapped around the ring. Both at Eloy. The first time I pulled the control line down and it would not go back up without shaking. I had collapsed my slider, but was planning on pulling it down past the toggles after I got myself going the right direction in high traffic. Well, the slider was at the slink and covered the "wrap". I was able to shake the toggle enough to make it go most of the way back up, but not all the way because once the tension was reduced at the top end there was not enough pull. So I was unable to let go of the other toggle to inspect the mal (remember traffic and a canopy that wanted to turn). So I decided that since the toggle would go down, but not up, and I tried moving it a few times, I would just flare a tad high and bail to rears if the toggle got stuck. Landed on my feet near the tunnel.

When I landed the wrap fell off the ring due to the lack of tension. And the ring "sucked back in" the riser enough that it just did not appear to be able to snag... So I looked at my mal-less rig for a while, asked friends to inspect, and we found nothing. So I thought it was just some kind of tension knot with another line...

Three jumps later, it happened again. This time I used my mouth to hold the other toggle down (to flight straight) so I could inspect the mal. Sure enough the line was wrapped around the rig and I could clear it pretty easy - but it required pulling the slider down and doing some random turns to make it happen. I tacked the slinks upon landing.

Ironically, on my new PD slinks I have not tacked them down, but they are staying where they need to. I guess I never learn, huh? But at the same time, the round ring of Aerodyne seemed to be more prone to exposing itself. (Slippery thin ring versus thick textured tab) The thick PD tab just does not want to come out of the riser...

So - I will say - it is very important that the Slinks be installed correctly, even if it is not for structural issues, but for snag issues. If your tabs want to come out, tack them right away so they will reset their "set" at the proper location... I don't want to badmouth the metal ring design, but I think they are more likely to slip out of the riser and require the tack recommended in the instructions.

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[I had the Aerodyne style slink. My first rigger who assembled the rig said, "These can be tacked but instead I prefer just aligning them before each jump for a few jumps until they set in and stay in place on their own. That way you can change your canopy without the tack being replaced." (Of course the reserve was tacked)



I've got a set of PA soft links (brass ring). Thought about doing it that way, (this was before tacking was recommended) but then realised that a quick single loop tack through the center of the ring would keep it from rotating. Worked like a dream...

As to changing canopies... If you can afford multiple canopies, why not spring for the extra set of risers? Much easier to change out at the risers than the links. And (if you are careful) taking out a single turn tack is not a problem.

JW
Always remember that some clouds are harder than others...

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they should be replaced when ever they look worn.

i have been abusing a set of pd reserve slinks on my slider up base rig for about 150 jumps and they are starting to look a bit melted. its something i have also noticed on tandem mains using slinks.
with a hard opening the slider grommets come down hot, smack the slink hard and stop right there in the same place every time because of the wider risers. it leaves a small patch of slink and riser melted and with repeated heatings and beatings the patch of nylon melted gets bigger , the edges of the melted patch can get a little rough and the risers work against the slink right there where its rough.
personally i think slinks are a bad idea for tandems ,when i have changed line sets on tandem mains with slinks i have seen risers that really shouldn't have been in the air for a while.
even on 1 inch sport risers, if you get hard openings look out for the glazing where the risers meet slink and slider.
i love using the slinks on my base canopy because the damage from the slider is going to be done somewhere,the grommets are hot. the slinks allow the grommet to pass right off the lines so they don't get scorched and I'm using slider bumpers i got from a set of pd main slinks to protect the risers and they work nicely so the risers are fine. i just accept i'm going to be keeping a constant eye on them and changing the slinks more often than the lines.
just in case anyone was thinking of flaming me, in using slinks on a base rig i consider myself a test pilot.

if you leave the tab hanging out then the slider is going to knock on the slinks weakest point every time so its going to wear out sooner and surely its just a matter of time before it causes trouble between the slider and the control line.

if you leave the tab hanging out and you have brass grommets on your slider then the tab will leave little dents in the grommets which will deteriorate the lines quite quickly , even the pd slink tab will dent a brass grommet over time.

i think that slinks generally should be changed a lot more often than people are currently doing, they take a hell of a beating and they dont cost much. and if the person jumping it doesn't maintain the gear then maybe metal links are the best option.
my hovercraft is full of eels.

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