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sundevil777

Lubricating the 3-ring loop

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I think the value of lubricating the inside radius of the 3-ring loop where it contacts the release cable is important and underappreciated. Of course lubing the cable in general is important, but I think a substantial part of the overall force to pull a release cable is due to the drag right at the loop, and applying lube to the loop is a subject worth addressing.

The attached pic provides some evidence to support my claim. Mr. Booth used it many years ago in a thread where he advocated the benefits of the traditional, large 3-ring system over mini rings.  The different graphs were intended to show how pull force varies with the load at the loop, with the different systems having a different mechanical advantage (and some effect from inconsistent construction affecting mechanical advantage) which results in different loads at the loop.

While on the subject of reducing pull force, we might as well touch on what I think is now widely accepted that silicone lube is best instead of some type of oil or other product. I think the gel type silicone grease, such as the cypress loop grease is better than the spray type. Other threads have devoted a lot of discussion about food grade silicone sprays, but the gel makes more sense to me. Please correct me if I am wrong.

Perhaps there would be fewer instances of hard pulls and only one side released if lubing the loop were standard practice. I can't remember it being emphasized in all my years. I put the gel grease right on the inside radius of the loop, what do you think?

pull_force_comparison.JPG

Edited by sundevil777
edited to include attachment

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(edited)

It's an interesting idea. I see two questions, the first being how much would it help, the second being what down sides there might be. The friction from the loop of course plays some part in the pull force but I think a lot of it is from the bend in the cable as the loop tries to pull the cable through the grommet. It doesn't have to pull it all the way through. All it has to do is cause a small bend there at that point. As you try to pull the cable through that point your trying to pull it through a rather sharp bend. Pinch a cable between your fingers, pull. Not a problem. Take two fingers and your thumb and put a small sharp bend in the cable. Try to pull it through that with out relaxing your fingers, much harder. The sharper and greater that bend the harder it will be. In reality it's probable a high peak force followed by a more moderate but still high load from say a spinner. Cable gets a kink and although the loop can move it's now pulling on a point on the cable with a kink and it's harder to pull that bend past the grommet. I think a better solution might be to reexamine the end on the housing. I was really interested when Mirage came out with their housing ends. Why should we be stuck with #0 grommets. That hole could be smaller. At first they had sharp edges and there were some marks being left on cables, They radiused them and fixed that problem but that makes the hole "wider". I just think that hole could be smaller. Large enough for a twist in the line to pass through but smaller then we have now. 

 

If you put a lube or grease on the loop I'm worried that it will be more prone to pick up dirt and grit off the floor. They are a wear point. It would be an issue. I wonder if a "dry lube" Like some of the things we use for magazines in fire arms would be better. Generally you spay it on and it evaporates leaving behind a Teflon or some thing like that. Point is that it's a dry surface that does not attract dirt. I have not tried this. I am not advocating this. It's just an example that popped into my head as I was setting here typing. For all I know these things might eat nylon. Just tossing it out as a thought.

 

This is an interesting idea but you should test it before we all go out and do this to our risers. Take a couple of really active teams, 1000 jump a year guys. Convince them to let you do this to ONE of their risers. All the left hand risers, not the right. Let them put a thousand jumps on those risers and at the end of the year, when they should be throughing them out any ways, evaluate them. Including pulling that loop to breaking on a test stand. Compare the two sides. Do this in a few places like Eloy where it's dusty and some place not. I'd like to see how the wear changes. Hell I could probable convince Phil to pull them for you.

 

And to be fair you would need to convince the manufacturer to sew up some riser ends, at least the loops as a brand new base line. I haven't done this but I might bet that the new ones would break at the sewing and the old ones at the end or at a wear point over the ring.

 

Lee

Edited by RiggerLee

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