Forums: Skydiving: Gear and Rigging:
Adding hard housings to risers

 


flashpipe  (D 19253)

Mar 15, 2013, 8:21 AM
Post #1 of 16 (1787 views)
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Adding hard housings to risers Can't Post

I've got a Mirage with a set of risers that don't currently have hard housings. I bought a set of hard housings from ParaGear and they're about 1 1/2" longer than the sleeve. I've seen some systems where the housing extend below the sleeve (like http://www.dropzone.com/...7405;t=search_engine), but this seems like a bit much. They're still about 1" from the 3 ring. Is it fine to go ahead and use them as long as they're tacked into the sleeve well? Should the end be tacked to the riser as well?
If not, is there any way to cut the cable housing shorter and add the ferrule back or cap the end?
Thanks!


mark  (D 6108)

Mar 15, 2013, 8:52 AM
Post #2 of 16 (1757 views)
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Re: [flashpipe] Adding hard housings to risers [In reply to] Can't Post

Best solution: get a pair of inserts that fit.

Next best: make the sleeves longer. You don't have to remove the old sleeves to do this.

Temporary solution: tack the lower ends of the inserts to the risers. You don't need to tack the upper ends.

As for cutting the cable housings to size, you'll need special tooling to crimp new ferrules to the cut ends. The old ferrules can't be reused, and you shouldn't leave the the cut ends uncapped even if you plan to use a generous amount of duct tape.

Mark


JohnSherman  (D 2105)

Mar 15, 2013, 2:18 PM
Post #3 of 16 (1654 views)
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Re: [flashpipe] Adding hard housings to risers [In reply to] Can't Post

Quote:
I bought a set of hard housings from ParaGear and they're about 1 1/2" longer than the sleeve. I've seen some systems where the housing extend below the sleeve (like http://www.dropzone.com/...7405;t=search_engine), but this seems like a bit much. They're still about 1" from the 3 ring. Is it fine to go ahead and use them as long as they're tacked into the sleeve well? Should the end be tacked to the riser as well?
If not, is there any way to cut the cable housing shorter and add the ferrule back or cap the end?
I don't know what you are trying to accomplish but Hard housing are not necessary and if not installed correctly, dangerous. They accomplish nothing. If you will keep your yellow release lubricated you will never have a difficult pull.

Assuming your risers will pass the ring alignment test, all of your release resistance is at the nylon loop which the yellow cable goes through. The friction between the loop and the cable can vary as much as 100% depending upon lubrication.
Lube your cable and forget the inserts.

To test do this: In a suspended harness bypass the loop and insert a lubed cable directly into the channel on the riser. Retain the loops with a temporary pin. Perform the 2 bloke test: One person hanging on each side of the person in the harness. Twist up the riser until the rings cone together at your chest. Pull the release handle. Observe the force required. Pull either of the temp pins and observe the force required. Repeat the test with the cable going through the loop. Repeat with housings in the riser channels if you are curious and have the time. You will have your answer before you get here.


mrj007k4  (D License)

Mar 15, 2013, 3:07 PM
Post #4 of 16 (1627 views)
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Re: [JohnSherman] Adding hard housings to risers [In reply to] Can't Post

http://www.youtube.com/watch?v=x67syhlBMKQ

Maybe hard housings would have helped here.


jumpsalot-2  (D 33093)

Mar 15, 2013, 3:36 PM
Post #5 of 16 (1609 views)
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Re: [mrj007k4] Adding hard housings to risers [In reply to] Can't Post

In reply to:
http://www.youtube.com/watch?v=x67syhlBMKQ

Maybe hard housings would have helped here.
In reply to:
Never give up, eh ? Smile


riggerrob  (D 14840)

Mar 15, 2013, 4:06 PM
Post #6 of 16 (1590 views)
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Re: [mrj007k4] Adding hard housings to risers [In reply to] Can't Post

In reply to:
http://www.youtube.com/watch?v=x67syhlBMKQ

Maybe hard housings would have helped here.

........................................................................

The unusual thing about those main risers is the large amount (about 3 inches) of yellow cable exposed (between the white loop and the end of the sleeve).
It looks like the right main riser was rubbing directly on the left cable.
That has GOT to mess with pull forces.
Using mid-1990s sewing techniques it is possible to sew the bottom end of the sleeve to the bottom edge of the confluence wrap. Why you would leave any more cable exposed is s mystery to me?????


Deyan  (D 322)

Mar 15, 2013, 4:31 PM
Post #7 of 16 (1582 views)
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Re: [riggerrob] Adding hard housings to risers [In reply to] Can't Post

In reply to:
Using mid-1990s sewing techniques it is possible to sew the bottom end of the sleeve to the bottom edge of the confluence wrap. Why you would leave any more cable exposed is s mystery to me?????

The production time is less + you will be amazed how many 20 years old mini risers are still in use...People are still jumping mini risers without tape 3 reinforcement Crazy


JohnSherman  (D 2105)

Mar 15, 2013, 4:33 PM
Post #8 of 16 (1580 views)
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Re: [mrj007k4] Adding hard housings to risers [In reply to] Can't Post

Quote:
Maybe hard housings would have helped here.

I don't think so. But a lubed yellow cable would have. I have had this happen to me. I also have had to put out a reserve without being able to cut away. I did an extensive investigation and found what I am telling you.


JohnSherman  (D 2105)

Mar 15, 2013, 4:37 PM
Post #9 of 16 (1574 views)
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Re: [Deyan] Adding hard housings to risers [In reply to] Can't Post

Quote:
People are still jumping mini risers without tape 3 reinforcement

I still make them that way. Smile

Reason: it doesn't help, there have been failures with the Type 3. The secret is in the rolled edge at the ring. Wink

See you next week!


Deyan  (D 322)

Mar 15, 2013, 4:46 PM
Post #10 of 16 (1568 views)
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Re: [JohnSherman] Adding hard housings to risers [In reply to] Can't Post

In reply to:
I still make them that way. Smile

I didn't know Unsure The "newest" Racer I inspected was from '93. Learning something new every day will keep the doctor away Tongue


riggerrob  (D 14840)

Mar 16, 2013, 4:17 PM
Post #11 of 16 (1422 views)
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Re: [Deyan] Adding hard housings to risers [In reply to] Can't Post

In reply to:
In reply to:
Using mid-1990s sewing techniques it is possible to sew the bottom end of the sleeve to the bottom edge of the confluence wrap. Why you would leave any more cable exposed is a mystery to me?????

The production time is less + you will be amazed how many 20 years old mini risers are still in use...People are still jumping mini risers without tape 3 reinforcement Crazy

.....................................................................

Amazing!
Consider that we saw reinforced mini-risers during the 1993 PIA Symposium and 3-Ring Inc. published production instructions in 1998.
It is amazing that people are still jumping 20-year-old risers.
How they convince Tyep 17 webbing to last that long is a mystery to me. Type 17 webbing frays pretty quickly.
... or does that mean that people are not doing enough jumps per year to wear out Type 17 risers?????
I have not seen a pair of mini-risers still airworthy after a thousand jumps.
50 jumps per year is probably not enough to stay current on fast canopies.
Which is worse: jumping antiquated equipment???
... or not doing enough jumps to stay current????


williammonk

Mar 18, 2013, 3:22 PM
Post #12 of 16 (1295 views)
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Re: [JohnSherman] Adding hard housings to risers [In reply to] Can't Post

In reply to:
Quote:
Maybe hard housings would have helped here.

I don't think so. But a lubed yellow cable would have. I have had this happen to me. I also have had to put out a reserve without being able to cut away. I did an extensive investigation and found what I am telling you.

Why don't you think they'd of helped, John?

I haven't done too much research into the subject... Do you think that the hard housings would have crushed, crimping around the cable?

My risers have hard housings and I always thought they were a good safety measure. I keep my cables appropriately lubed as well.

I'm interested to know what you found in your research.

William.


JohnSherman  (D 2105)

Mar 19, 2013, 8:57 AM
Post #13 of 16 (1218 views)
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Re: [williammonk] Adding hard housings to risers [In reply to] Can't Post

Quote:
Why don't you think they'd of helped, John?

The red reinforcement tape was a mis-diagonosis by the folks who used it. History has proven that. The root cause for the Type 17 failure was the failure to fold the selvage edge under where it contacted the middle ring. Allowing the selvage edge to be exposed to the place where the middle and harness ring come together, is the root cause. At this place, when the rings load, the two rings actually work like a guillotine slicing the type 17.
I had a pile of rejected Type 17 risers (Someone had burned a hole too big for the grommet) and they were not usable. I put each one, in turn in the dyno. I could not fail them. Then I exposed the selvage edge and they failed. Under a glass the failed surface was like a scissor had cut it. I repeated this experiment a large number of times.

I published a paper in 1993 on the subject but people would rather listen to uninformed gurus speculation than read: http://www.jumpshack.com/...RE&SortBy=DATE_D

The red reinforcement does only one thing. It reduces the mechanical advantage of the ring set due to the increase thickness of the webbing. Parachute Labs. has never had a Type 17 riser failure. Risers with the red tape have failed.
Lubrication of the cable is paramount. Lubrication reduces friction all along the length of the cable. Most importantly at the last 8 inches or so. There is no amount of dirt or gunk within the housing that can cause the cable to bind. The tolerances are too great. The housings are totally unnecessary. Loop load is the killer for un lubricated cables.
Do the test in post #3 of this thread.


riggerrob  (D 14840)

Mar 19, 2013, 6:04 PM
Post #14 of 16 (1126 views)
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Re: [JohnSherman] Adding hard housings to risers [In reply to] Can't Post

I suspect that part of the problem was the thin RW-7 harness rings that were fashionable during the late 1980s.
Note that Parachutes de France built their first slotted, mini, harness rings the same thickness as RW-0 and RW-1.
Also note that current-production RW-8 mini-rings are about the same thickness as RW-0, RW-1, RW-6 and RW-10.


RiggerLee

Mar 19, 2013, 8:07 PM
Post #15 of 16 (1104 views)
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Re: [riggerrob] Adding hard housings to risers [In reply to] Can't Post

Isn't the RW-10 a bit beefier then the others listed? The really nice one is the RW-9 Now that's some beef and the... I think it's the 1076, that goes with it is a strong little bastard. I just wish that it was longer like the Aerodyne RW-2 variation so that it would have better leverage and not transfer load to the third ring. But the Aero ring is just too light a gauge. It fails by bending and wrapping around the RW-9.

Even with an RW-10 you can still see cutting at the wrap of the middle ring. The larger radious does help but we still saw damage there. Ultimently the failure occurred at the small ring as it tore lose from the riser but if it had not failed there I think it would have cut the riser around the RW-10

I've seen risers fail in skydiving. But the odd thing is I've never seen them fail at the grommet. I've seen them break in all other ways but not there. Weird? I've seen them streatch. Looked scarry. But I've never seen them fail there. Every body said they did but all I ever heard was vague stories about how every one knew that they failed there and then I watch one break the tape on the small ring or break a riser leg above the confluence wrap, or well you get the idea. Not saying it hasn't happened but I've never seen it.

With out a doubt there have been hard cut aways. but to be honest I've always been a little skeptical about the real cause or if it's a combination of things. Some of the "solutions" have seemed... well they made people feel good. I guess that's important but some of them I don't know about. Plastic tubes? If you've got enough force to be a problem then bending a plastic tube into a spriral under that much force sounds like a recipe for a real disaster. Hard housings that aren't long enough where the cable sticks out the end. What if the edge digs in to the cable beyond that housing? What about housings that stop above the confluence wrap and get bent against the cable making rough spots in the coating?

Hell what about all the other problems that can contribute to the whole system? Drag in the housing? Housings hard tacked to the harness under load? Bad geometry? I'm just not sold on this as the end all solution and that any one that doesn't sew after market hard housings in to there risers is going to bounce on the very next load.

By the way. I have numerous cut aways on a javelin with the dreaded soft housings. OMG I'm going to die. Never had a problem. Still jumping them.

Lee


flashpipe  (D 19253)

Mar 22, 2013, 7:21 AM
Post #16 of 16 (954 views)
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Re: [RiggerLee] Adding hard housings to risers [In reply to] Can't Post

Thanks to everyone for the great replies. This was actually for a rigging customer who had requested the inserts for his rig and his wife's. I don't actually use the inserts on my rig. I just cut the ends of the cables so there's only about 2" of stowed cable in the sleeve and I keep them cleaned and lubricated.

Anyway, I put his inserts in (tacked them in well), and told her that they just didn't fit into her existing risers and that they were probably overkill for both of their rigs since neither of them jump high performance canopies. But, if she really wants them, she could get new risers because almost all new risers have the inserts now.

Thanks again for all the helpful input!

Blue skies,

Brian



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