Condition of microline reserve cable on Sigma

[alexey 6]

Is it still in use?
Is it only for Sigma, or for Micron too?
How are field feedback about them?

Sorry for bad English

Lexa

[Rdutch 0]

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Is it still in use?
Is it only for Sigma, or for Micron too?
How are field feedback about them?

Sorry for bad English

I have one on my Vector 304

Ray
Small and fast what every girl dreams of!

[klingeme 0]

The Spectra Reserve Cable has been held up with the FAA. We are ready to start producing them, however, we can not until we get the OK from the FAA (it is part of the TSO).

Mark Klingelhoefer
United Parachute Technologies

[diablopilot 2]

Is each one still pull tested to the same limits as the traditional type cable?

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You're not as good as you think you are. Seriously.

[klingeme 0]

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Is each one still pull tested to the same limits as the traditional type cable?

Actually, the current (metal) ripcords are tested to 600 lbs, but the spectra is tested to break above its rating of 1000 lbs. (typically around 1,100 lbs when it breaks).

Mark Klingelhoefer
UPT

[diablopilot 2]

Forgive me if I'm repeating myself, but I want to make sure I understand.

In respects to the new Spectra based ripcord, is each newly manufactured unit tested to a specific test limit? i.e. each unit pull tested to 1000lbs. Or is a sample of a patch pulled and tested?

I am under the impression that with a traditional ripcord, each is tested to a pull of 600lbs or 300lbs if not to be used with an RSL.

I'd assume that the weak point (typical breaking point) in a Spectra ripcord is at a stitch or finger trap.

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You're not as good as you think you are. Seriously.

[klingeme 0]

Sorry for the delay in getting back to you on this one, with everyone away at PIA, I've been busy.

I just spoke with our engineers, and in the pull tests we have done with assembled ripcords, we are finding that they break at between 900 and 1000 lbs. Strangley enough, they have not been breaking at the bartack or finger trap, they are breaking in the center of the ripcord (in the middle of the elastic). We are still determining the best wat to test each individual ripcord for when we start selling them, but all will be tested to the same standard we test all of our standard ripcords (600 lbs for 3 seconds).

Mark Klingelhoefer

[AndyMan 7]

I would have guessed that wear from friction is a more common scenario than extreme pull forces.

How is the system designed to mitigate the effects of friction? What are the wear characteristics of this system?

Also, how has the testing been changed to reflect this? While a pull-test makes perfect sense for a steel cable, I would think wear tests over the long term would be a much bigger concern. How is this being addressed?

_Am

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You put the fun in "funnel" - craichead.

[Rdutch 0]

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I would have guessed that wear from friction is a more common scenario than extreme pull forces.

How is the system designed to mitigate the effects of friction? What are the wear characteristics of this system?

Also, how has the testing been changed to reflect this? While a pull-test makes perfect sense for a steel cable, I would think wear tests over the long term would be a much bigger concern. How is this being addressed?

_Am

Wear isnt as much of a fattor as you would think. UPT has a demo rig where a regular rip cord, and a Spectra (Its coated also) rip cord both have a nice amount of weight added to the end of them. This demo is used to show the reduced pull forces of the spectra rip cord. This demo has been around forever and is pulled often. It hasn't shown wear. Im sure Bill has done considerable wear testing before releasing the cable. He has had this idea for over 10 years. The spectra rip cord is a lot more secure than the metal one, is much stronger, and has an amazing difference in pull strength. If you ever try the demo you would be amazed at the difference.

Ray
Small and fast what every girl dreams of!

[diablopilot 2]

Ray, the problem is one of wear and tear in the field.

Put that fabric ripcord on a student rig and have them land repeatedly over the course of a couple years in a sandy landing area.

Then try the same for an up jumper rig where maintenance may not be the jumpers first concern.

Thats going to be the true test of survivability of the item.

We're not seeing a problem with pull forces on the current ripcords in the industry and they are more durable. The only motivation I see for this change is cost, and I don't think thats enough of a reason to change.

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You're not as good as you think you are. Seriously.

[riggerrob 558]

Cost is a big problem.
Skydivers are always whinging about the cost of gear!
Ripcords are a major production bottle neck.

[riggerrob 558]

As long as you start with metal housings - that are smooth inside - and over-strength Spectra cord - with some sort of latex, resin or silicone coating - the chances of friction are minute.
Oh! Friction only occurs when you rub two things together.
Since the average skydiver never slides his ripcord, it should last a million jumps.
In comparison, even the 1,000 pound Spectra suspension lines - on tandems - are still structurally sound when we replace them after 300-400 jumps.
I have seen many Spectra lines on main canopies that had 1,000 jumps are were still almost as strong as when they were new.

The primary friction issue is smooth insides of housings.

[riggerrob 558]

In respects to the new Spectra based ripcord, is each newly manufactured unit tested to a specific test limit? i.e. each unit pull tested to 1000lbs. Or is a sample of a patch pulled and tested?

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>..

That depends upon what the manufacturer's (TSO) quality control manual specifies.
Some manufacturers test every single ripcord, while others only test a few from each batch.
Both methods work as long as you have honest people who follow the manual.
The QC manual should include a schedule for inspecting tools for wear.

[AndyMan 7]

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The primary friction issue is smooth insides of housings.

That's my biggest concern, because even if the housings are smooth the day they leave the factory, there's no guarantee that they'll remain that way throughout the life of the rig.

We already tell people to verify their steel ripcords have free movement because debris can cause the system to lock up. That same debris can cause wear on a soft cable. Sand and small pieces of gravel already pollute the hard housings. What will the long term effect of this be against a soft cable?

I have to assume that UPT has already thought this through. I'm hoping they'll fill us in with what they found.

_Am

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You put the fun in "funnel" - craichead.

[pilotdave 0]

I thought the original idea came from the Sigma drogue release handles (the spectra lines that pull the pins). They had enough field testing with those to have confidence that they'd work for reserve ripcords too. I dunno... the idea scares me just like soft links do, but I use those on my main and reserve now.

Dave

[Rdutch 0]

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The primary friction issue is smooth insides of housings.

That's my biggest concern, because even if the housings are smooth the day they leave the factory, there's no guarantee that they'll remain that way throughout the life of the rig.

We already tell people to verify their steel ripcords have free movement because debris can cause the system to lock up. That same debris can cause wear on a soft cable. Sand and small pieces of gravel already pollute the hard housings. What will the long term effect of this be against a soft cable?

I have to assume that UPT has already thought this through. I'm hoping they'll fill us in with what they found.

_Am

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Wear would only come from use, sand inside the housing just sitting there wont be a problem. Fortunately your cables would be inspected every repack. Wear would come from use, only a minute amount even if the housing had a lot of sand inside it. Fortunately Use means an inspection and a repack. I have the spectra cable on my rig and I like it very much.

Ray
Small and fast what every girl dreams of!

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[crazydiver 0]

Pilotdave is correct in thinking about it from the Sigma drogue release standpoint. Sigma drogue releases are constructed of the same material as the new reserve ripcords and the sigma drogue releases that I've seen have literally been used and used for thousands of jumps with no wear. That means they get yanked on THOUSANDS of times and lord knows that tandem gear gets dirty, beat up, and destroyed just as much as student gear and the drogue release ripcord still holds up with little to no wear. I've helped replace two Sigma drogue release ripcords ever in over four years of rigging Sigmas and that was due to the elastic shock cord wearing out from so many pulls and you can only replace the shock cord so many times before you destroy the ripcord material. Aside from replacing the shockcord, though, the ripcord still holds true even if that shock cord breaks. Reserve ripcords only get pulled here and there and get inspected at each repack. That's nothing compared to the thousands of jumps you can get out of a sigma drogue release.

After a thousands reserve ripcord pulls...ANY reserve ripcord should be retired ;)

This is just speculation, but I'd venture to say that a standard capewell reserve ripcord would rust out long before a spectra reserve ripcord would wear out.

My 2 cents.

Cheers,
Travis