Apr 22, 2013, 7:06 PM
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Cutaway cable cleaning mistake
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I cleaned the cutaway cable with Break free CPL..... I just realized it might be a bad idea since I saw that contains some petroleum derivates. After spraying it on the cable I wiped multiple times so that it didn't go in the housing wet.....but I'm still concerned.... Any suggestions/raccomandations?
One recommended cleaner is 3 in 1 oil. CPL should be fine but check for any tackiness of the coating. If you'd used brake CLEANER (or gun cleaner equivalent) then I'd be worried. It used to have methylene chloride in it. (carcinogen - doesn't have it any more - doesn't work as well)
Also when and if you do use silicon spray get food grade. The other grades have light weight hydrocarbons that you don't need and might do harm (but probably not).
I just realized it might be a bad idea since I saw that contains some petroleum derivates. After spraying it on the cable I wiped multiple times so that it didn't go in the housing wet.
The Yellow coated cable is coated in pure Nylon and requires lubrication on a monthly basis at minimum. I recommend weekly as stated in the Racer manual. We Skydive on a weekend basis and the end of the month could come in the middle of the week. The recommended lubricant is petroleum, silicone is acceptable but it hydrolyzes in Nylon in about a week requiring reapplication. If you don’t have any 3 in 1 oil handy just wipe the oil from your dipstick with your fingers and apply it to the last 7 or 8 inches of the cable. This is to make sure you lube the part of the cable which goes through the nylon locking loop. Test: This test should be part of the “Jumpmaster or Pin check” before boarding. Pull one or both of the cables out of the riser channel and run it between your fingers. If it “Squeaks” like freshly shampooed hair go back and oil it. There should be no resistance or “Squeak” from the cable. If you have a Red coated cable it is coated in pure FEPT Teflon and requires no maintenance or lubrication. A general word about 3 ring cables and housings: The black “goop” which you see on some of your cables is good. It is the residue from the cutting oil used in the housing manufacture. It is a lubricant albeit with high viscosity. Many people worry about dirt sticking to the cable because of the stickiness of the oil and try to remove it. This is misguided and not a problem. One military orginization wiped the cable clean every 90 days for several years before they got all of the cutting oil off of the cable and out of the housing. Then they began having cutaway problems. They now lubricate every 90 days. Test: With a cable and housing separate from a rig. Oil the cable until is drips with oil then drag it through the dirt and sand. Fill the housing with dirt and sand. Insert the cable and coil the housing to its minimum diameter. Pull the cable out and observe the effort. The worst thing you could have on your rig is a dry cable. The point of loading is the nylon loop. Loop tension effect is doubled with a dry cable. I know all of this because I have had a “No Cutaway” from a 3 ring. It occurred many years ago shortly after the Yellow cable was released to replace the clear cable. The Yellow cable was touted, by the supplier, in writing, as being Teflon impregnated and requiring no lubrication. This was not accurate. It had no Teflon was pure Nylon and it required lubrication as above. Because of this bad info we stopped lubricating new rigs. After my experience I tested some 30 rigs which were ready for shipment. Two of us did the test. One held the rig and one held the risers with tension. The one with the rig pulled the cable or should I say TRIED to pull the cable. None would release. We oiled each in turn and they all worked find. This experience led to a series of extensive test where we built a simulator for the configuration. From those test we learned the relationship between the cable, housing and oil and developed the procedures reported here. BTW: The only damage petroleum does to nylon is to stain it, which can be removed . There is no loss of integrity.
(This post was edited by JohnSherman on Apr 23, 2013, 8:11 AM)
Thank you for this information. Do all manufacturers use the "Red" cable now ?
If not, would you happen to know why?
My memory is that the red cable was said (by some, obviously not the folks at Jump Shack), that it was not as rigid and would therefore be deflected more by the tension of the white loop. that deflection is of course one factor in the force required to operate the release.
I avoid a good part of this issue by continuing to be old school and using large 3 rings. Less tension on the loop, less deflection of the cable, more tolerance on the construction of the riser.
Thank you for this information. Do all manufacturers use the "Red" cable now ?
If not, would you happen to know why?
No they don't, I don't know why. But I do know we are the only ones using it as we have to have it custom made. Maybe ask one of them and see if they have even heard of it. If they have be ready for some of the best BS you hve ever heard.
In reply to:
My memory is that the red cable was said (by some, obviously not the folks at Jump Shack), that it was not as rigid and would therefore be deflected more by the tension of the white loop. that deflection is of course one factor in the force required to operate the release.
Wow! I hadn't heard that one. It's amazing what some people will say to sell a rig. The core wire of the Red coated cable is the same core wire as the yellow. The rigidity is the same.
Thank you for this information. Do all manufacturers use the "Red" cable now ?
If not, would you happen to know why?
No they don't, I don't know why. But I do know we are the only ones using it as we have to have it custom made. Maybe ask one of them and see if they have even heard of it. If they have be ready for some of the best BS you hve ever heard.
In reply to:
My memory is that the red cable was said (by some, obviously not the folks at Jump Shack), that it was not as rigid and would therefore be deflected more by the tension of the white loop. that deflection is of course one factor in the force required to operate the release.
Wow! I hadn't heard that one. It's amazing what some people will say to sell a rig. The core wire of the Red coated cable is the same core wire as the yellow. The rigidity is the same.
Other mfgs have obviously heard of the red coated cable, as shown from the previous link to an old thread. I think you do your reputation unnecessary harm by these dismissive statements.
The rigidity of the cable depends on the inner core and the outer layer. Is it possible that the yellow coating is more rigid than the red? Perhaps my memory is wrong about this aspect of claimed rigidity difference.
(This post was edited by sundevil777 on Apr 23, 2013, 12:44 PM)
The rigidity of the cable depends on the inner core and the outer layer. Is it possible that the yellow coating is more rigid than the red? Perhaps my memory is wrong about this aspect of claimed rigidity difference.
Durometer is the term used to describe the hardness of the coating. Booth stuck his fingernail in it and declaired it to soft. I had it tested and found that the durometer varies for both within the same range. It has been is service now for maybe 20 years and other than a cracking problem from a former vendor many years (1996+/-) ago have had no problem. There is probably 20,000 units in service.
(This post was edited by JohnSherman on Apr 23, 2013, 1:06 PM)
John, thank you for your detailed explanation. I want to make sure I have your directions correct for my own maintenance procedures. Please confirm this is what I should be doing for normal maintenance (not testing, etc.):
Use standard 3-in-1 multipurpose oil Pull cutaway cables completely out of rig Coat last 7-8 inches of cable (enough to clear the nylon loop) Replace cutaway cable/handle in rig, correctly assembling 3-ring, etc.
Or should I be coating the entire cable? Do you let it drip or lightly wipe it off so there isn't excess oil?
Use standard 3-in-1 multipurpose oil Pull cutaway cables completely out of rig Coat last 7-8 inches of cable (enough to clear the nylon loop) Replace cutaway cable/handle in rig, correctly assembling 3-ring, etc.
Or should I be coating the entire cable? Do you let it drip or lightly wipe it off so there isn't excess oil?
Correct oil. If you have the cable out of the rig why not wipe it clean and apply a fresh coat of oil to the entire cable(s)? That is the military way and probably the best practice. A lite coat will do. I think of a lite coat of oil as I did in the Army when I cleaned my rifle. The loop is where the bad friction occurs and needs lubrication the most and it is usually located 6.5 inches from the end of the cable. However, it won't hurt to lube it all.
John
faulknerwn (D 17441)
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Apr 23, 2013, 1:34 PM
Post #20 of 43
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I have 22 ish reserve rides these days. It's WAY easier to cutaway when using the red cable than the yellow. I have encouraged many of the smaller female friends I know ( especially them) to switch to the red cable. It's a very noticeable difference in cutaway forces.
Newbie researching for first gear purchase here. I prefer maintenance-free to maintenance-required. Can I just get a red cable from Jump Shack regardless of what rig I buy, and swap out the standard yellow cable? Would this present any issues? Are the red cables or their housings a different size or something? My limited knowledge suggests that the only issue would be the lengths of the cables?
I'm trusting that both (properly-maintained) yellow and red do an adequate job, as they're both still on the market after so many years. If one was a death trap, we'd know about it by now, no?
Use standard 3-in-1 multipurpose oil Pull cutaway cables completely out of rig Coat last 7-8 inches of cable (enough to clear the nylon loop) Replace cutaway cable/handle in rig, correctly assembling 3-ring, etc.
Or should I be coating the entire cable? Do you let it drip or lightly wipe it off so there isn't excess oil?
Correct oil. If you have the cable out of the rig why not wipe it clean and apply a fresh coat of oil to the entire cable(s)? That is the military way and probably the best practice. A lite coat will do. I think of a lite coat of oil as I did in the Army when I cleaned my rifle. The loop is where the bad friction occurs and needs lubrication the most and it is usually located 6.5 inches from the end of the cable. However, it won't hurt to lube it all.
John
Thanks for the information you've provided in this thread. I've learned a lot. For example, it never occurred to me that the oil is mainly to reduce friction right at the loop. I suppose I always considered it to be friction in the hard housing that snakes up to this point. I hadn't even consider friction at the loop to be an issue. Now I know.
faulknerwn (D 17441)
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Apr 23, 2013, 7:07 PM
Post #23 of 43
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I avoid a good part of this issue by continuing to be old school and using large 3 rings. Less tension on the loop, less deflection of the cable, more tolerance on the construction of the riser.
Can somebody please elaborate on this? Is it correct that large 3 rings reduce cutaway pull forces?
Yes, that's correct. They act like levers - the longer the lever the greater the mechanical advantage. Think of prying something open with a screwdriver vs prying it open with a 3ft pry bar.
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