I HAD NINE CUTAWAYS IN ONE DAY!!

[SpeedRacer 1]

Yep, that's right. Do you think there might be something wrong with my packing??

I went to Chambersburg, PA for Safety Day. Met dzdiva there! I couldn't jump (I'm not current & neither is my reserve) but I went to all the seminars.

It was great! I am really glad I went, the seminars were very informative. During the last seminar JR (the DZO) gave a demonstration of cutaway cable housings. I had asked him previously if I could have my rig hooked up to a hanging harness so I could practice a cutaway.

So JR used me as a guinea pig during the seminar. He hooked up my rig to the hanging harness and hooked a hanging scale through the cutaway handle. He had me cutaway while someone looked at the scale to see how much tension was being applied. Then he had me do it again with cable housings inserted into the risers, first with plastic housings, then with steel housings.

We demonstrated those same three combinations with me hanging normally, then with two line twists, then with two line twists at 2 Gs. We simulated 2 Gs by having a guy who weighed about the same as me hanging onto my back.

The results were amazing.
When I was just hanging straight, I could cutaway with about 5-10 pounds (closer to 5) of force, regardless of the presence of cable housings.

With two line twists introduced, results went as follows:
No housings: 45 pounds of force (use two hands, folks!)
Plastic housings: 10 pounds
Steel housings: 5-10 pounds.

With 2 line twists plus 2 Gs:
No housings: Off the scale. Scale only measures to 50 lbs, but there was still room for the needle to go up above the 50 lb mark. Basically, I had the needle slammed all the way up against the top, well beyond the 50 lb mark.

Plastic housings: 25 pounds

Steel housings: 5-10 lbs

This is really important, folks. If you've got line twists, suddenly it takes 10 times as much pressure to cutaway. Plastic housings help a lot, but if you're in a spin, you're gonna have G-forces, which can compress the plastic when the risers are twisted against each other. Steel housings do not compress, you can't even flatten them with a hammer.

Moral of the story: Get some f&*king steel housings in your risers!! They don't cost much to get, they're an amazingly simple thing & they could save your life!! The difference in pull effort was AMAZING! Believe me, I know, I was doing all the cutaways!!

ps There was an article about these cable housings in Parachutist last year.

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This was posted in Talkback, but it was suggested I re-post it in G&R.

Speed Racer
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[wildblue 7]

Did you have standard or mini 3-rings?

it's like incest - you're substituting convenience for quality

[SpeedRacer 1]

I'm not sure (I don't have my rig here, it's getting a re-pack) but I think I have minis. I'd have to see a photo of them side by side to be sure.

Speed Racer
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[wildblue 7]

Quote

I'm not sure

Where's the "eek!" smiley? I'll let someone else flame you for not knowing your gear though

If they're the same size as about 90% of the sport rigs you see at your dz, they're probably mini. And with the forces you've described, probably mini.

RWS used to have a really good article on their site that I can't find anymore, so in the meantime (while we wait for Mr Booth) check out
http://www.relativeworkshop.com/support/tech_pullforce.html

it's like incest - you're substituting convenience for quality

[SpeedRacer 1]

I'm pretty sure they're minis. They're like everyone else's pretty much. I guess I don't see the "standard" ones so much so I didn't realize that my rings were small.

Speed Racer
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[billbooth 10]

Guys;

I tried every conceivable type of riser insert before I settled on flexible steel housings, with capped ends, almost 4 years ago. Nothing else works as well in all situations. But a word of caution...make sure the housings you choose have sealed off (capped) upper ends. Housings with open upper ends are far worse than no housing at all.

[Ruffles 0]

Anybody know if the Mirage G3 hard housings are metal or plastic?

[eames 0]

Metal.

[SpeedRacer 1]

Quote

tried every conceivable type of riser insert before I settled on flexible steel housings, with capped ends, almost 4 years ago. Nothing else works as well in all situations. But a word of caution...make sure the housings you choose have sealed off (capped) upper ends. Housings with open upper ends are far worse than no housing at all

bill, is this because the sharp edges can cut the cable, or what?

Speed Racer
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[SpeedRacer 1]

OK, I just read the other thread, now I understand. I will email JR & make sure that these are capped inserts.

Speed Racer
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[steve1 5]

Thanks for the info. I've got plastic ones now, but will get some steel ones with caps for both my rigs. I would think anyone with less upper body strength should have these, particularly on a high performance canopy. I knew a girl years ago who was barely able to pull her ripcord on a b-12 container. Steve1

[billbooth 10]

Quote

Quote

tried every conceivable type of riser insert before I settled on flexible steel housings, with capped ends, almost 4 years ago. Nothing else works as well in all situations. But a word of caution...make sure the housings you choose have sealed off (capped) upper ends. Housings with open upper ends are far worse than no housing at all

bill, is this because the sharp edges can cut the cable, or what?

Two reasons: 1. If the yellow cutaway cable protrudes beyond the upper end of the insert, even a minor riser twist will result in a no-pull situation, because the cable will be jammed against the "sharp" upper edge of the housing. 2. If the tacking that holds the housing in place comes loose, the capped end will stop the housing from sliding down the cable to the 3-ring closing loop, and possibly getting in the way.

This is a safety system for a safety system. Therefore, I can't believe anyone would not make it as safe as possible, and put out riser inserts without capped ends, but I've seen them.

[CanEHdian 0]

Bill, some manufacturers do not tack the inserts (they say it's not necessary)... as long as they are capped, do you see a problem with that?

Cheers,
CanEHdian

Time's flying, and so am I...
(69-way, 108-way and 138/142-way Freefly World Records)

[billbooth 10]

You MUST tack the inserts at the bottom to stop people from putting the yellow cable ends in the space between the tape channel and the metal housing, instead of correctly putting them in the metal housings. It depends on how tight the metal housing fits in the tape channel...but you can bet that if there is enough room, someone will do it. If the yellow cable is put into the space between the tape channel and the metal housing, it's a no cutaway situation, even without twists. l've said it before, and I'm sorry, but it looks like I'll have to say it again, "If people are going to copy my designs, they should at least copy them exactly".

[SpeedRacer 1]

alright all you fags: here's some more shit that may save yer lives:
From JR at Chambersburg, PA:

From JR in chambersburg:
Yes, all of the housings we used in the course were not capped. They were raw and unfinished. Allof the cables that go into the rigs are capped with an aviation grade rivet that is set with a rivet tool and are heat shrink wrapped.

Good question! Bill Booth is the inventor of the three ring and owns relative workshop who build the vector.

J.R. Sides

Speed Racer

Speed Racer
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[iam 0]

Sorry for being a pain in the ass, but i'm not sure what you mean with "capped" ends. Is it possible to post a picture of the two types showing the difference?

Many Thanks

Ian

"Don't ever knock on deaths door, just ring the bell and run away - it really pisses him off"

[nacmacfeegle 0]

Ian, I'm assuming, from Bills failure mode prevention discussion, that a "capped end insert" would be like a smarties tube, with the plastic cap off, but the cardboard end still in place. This would prevent the tube (should it become unattached from the riser) sliding down the teflon cable and fouling amongst the 3 rings, possibly preventing them from releasing.
Sorry no pics here.

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He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson

[SpeedRacer 1]

I apologize for the somewhat offensive preamble to my last post. I posted it last night, after coming from a certain pub that had Guinness for $2.00/pint Anyway, you know those cardboard tubes people use for storing posters? They have those plastic caps on both ends. Picture one of those tubes but with only one cap on it.
So the end of the cutaway cable would go in one end & not be able to come out the other end.

Speed Racer
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[iam 0]

Thanks, starting to get the picture....i think. Dont think i've seen any in the uk, or maybe i'm not looking hard enough.


Ian

"Don't ever knock on deaths door, just ring the bell and run away - it really pisses him off"