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Correctly made mini 3-ring riser pictures

 


billbooth  (D 3546)

Apr 9, 2002, 2:55 PM
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Correctly made mini 3-ring riser pictures Can't Post

CAUTION; Read this entire post before going to the pictures!
I have posted, at WWW.Relativeworkshop.com, under "Technical" - " 3 ring risers", photographs of "correctly" made mini 3-ring risers. Our website uses "frames in frames", so you may have to use both right side up and down arrows to view all 4 pictures. Three ring systems that match these pictures can be expected to release even a 6 "G" spinning malfunction with relative ease. The pictured riser was manufactured to my August, 1998 specifications. Mini risers manufactured before that date may differ somewhat, even those manufactured by the Relative Workshop. This DOES NOT mean that your risers are necessarily dangerous if they do not match these pictures exactly. It does mean that the closer your risers are to these pictures, the easier it will be for you to release a high "G", spinning malfunction. This specification change was made necessary by the advent of super high performance elliptical canopies, which generated super high performance malfunctions. If you jump more conventional canopies, risers made to these "new" specifications may not be necessary. These specs were immediately made available to all parachute manufacturers, worldwide. Complete construction plans are available from the Relative Workshop. Here's what to look for: Picture "A". The greater the gap (arrow) between the top of the harness ring and the bottom of the loop of tape which holds the smallest riser ring, the greater the pull force required to release the riser at high "G's". Picture "B". The shorter the white closing loop (arrow), the greater the chance of damaging your yellow breakaway cable during a hard opening shock, and the higher the release force under high "G's". Picture "C". If your short (right hand) breakaway housing won't stretch "upward" to accept riser stretch during a hard opening shock, you might damage or even "suck through" the yellow breakaway cable, making a cutaway hard or impossible. In addition to these parameters, I highly advise anyone jumping a highly loaded elliptical main to add short hard housings to your riser channels, to prevent the free ends of the yellow breakaway cable from being "grabbed" by severe risers twists. If you want to jump super high performance canopies, you need super high performance risers. You should also clean and lubricate your breakaway cables every month. WARNING: This is only a guide. Not every parameter which makes your 3 ring release as good as possible has been included.



rgoper  (C 32349)

Apr 9, 2002, 3:26 PM
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Bill:

good information, thanks for taking your time to post it here, i went to the site and checked it out.

Richard

"Gravity Is My Friend"





greig  (C 3113)

Apr 9, 2002, 8:32 PM
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Mr. Booth,
Any chance you could post some pics of 3-rings that are incorrectly or poorly constructed. Like "If your three rings look like this, you'd better hope you don't have a spinning mal" sort of thing?
Thanks.



diverdriver  (D 19012)

Apr 9, 2002, 8:40 PM
Post #4 of 19 (8431 views)
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http://WWW.Relativeworkshop.com

For us lazy people.




rapper4mpi  (D 21553)

Apr 10, 2002, 7:56 AM
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This is why I went with a Vector 3 M-series! Bill is the man!
-Rap



TEB6363  (D 16363)

Apr 10, 2002, 9:36 AM
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Re: Correctly made mini 3-ring riser pictures [In reply to] Can't Post

Mr. Booth. Thanks for posting the riser information. I had a question about using mini rings on a container with the large ring attachment (the good old 2-inch rings on the container).

I ordered my rig with the large rings because I wanted to be able to switch to type 8 risers if I wanted to. I like the feel and size of mini risers (type 17), so I currently jump a special made set of risers.

I have the larger 3-ring setup (usually assembled on type 8 risers) on my type 17 mini risers. I had this done because it feels like there is a lot less tension on the 3-ring while it is attached to the large ring on the rig.

Would this setup help to keep the pull tension down in a spinning mal?? The setup feels very smooth when I test the 3-ring and it looks like there is less binding. But I wondered if you had seen (probably) or tested this setup.

Thanks Bill.

Tom Berg
D-16363, AFFI2002, Sigma Tandem Rated and LOVE the Rig Smile

:::OK, Canopy is Open, No Traffic Around, .. Why are these "Extra" Lines Draping Down??, Damn!


billbooth  (D 3546)

Apr 10, 2002, 1:13 PM
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Re: Correctly made mini 3-ring riser pictures [In reply to] Can't Post

Tom;
I'm not sure I understand your question. If you have a complete "large" 3-ring setup on 1", type 17 risers, then the mechanical advantage of the system is the same as if you were using 1 3/4", type 8 risers. However, if you have a large ring on the harness only, and are using a normal mini 3-ring riser, then you have even less mechanical advantage than if you had a "small" ring on the harness. (ie. a normal mini 3-ring setup) The "fatter" cross section of a large harness ring lessens the lever arm" of the first riser ring, giving the whole system less mechanical advantage. The difference isn't drastic though, and if the riser is made correctly, everything should work just fine.



SkyMissy  (D License)

Apr 10, 2002, 1:34 PM
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Does anyone manufacture mini-risers "stock" with a large 3-ring setup?

I'm not the man they think I am at home, no;
I'm a rocket man.
Sky World


billbooth  (D 3546)

Apr 10, 2002, 5:50 PM
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Mike,
Since there are about 10 million possible variations of length, color, ring size, ring material, webbing size, dive loops, toggle types, and RSL options, nobody in their right mind stocks risers...except by accident...That is when you make 'em wrong because of all the stinking options. I looked through the Relative Workshop's rather large box of mistakes today, but sorry, not one set like you describe is there.
Bill Booth



Lindsey  (D 17865)

Apr 10, 2002, 7:07 PM
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I LOVE you billbooth....(flapping them eyelashes "flap, flap, flap")

Lscribblescribble

Eve was framed!
http://home.earthlink.net/~linzwalley


Kirils  (D License)

Apr 10, 2002, 7:15 PM
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Mr. Booth:
I am impressed you have taken time to participate in this dialog. Your reputation of a giant in the sport has gone up another peg! Kudos!! You are a benchmark for the industry!

Skydiving is not a static excercise with discrete predictability...


AndyMan  (D 25698)

Apr 10, 2002, 10:32 PM
Post #12 of 19 (8161 views)
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Thanks so much Bill.

My 2001 Javelin failed all three tests. That along with the fact that I need hard housings installed into the risers mean I'll be buying new risers ASAP.

_Am

ICQ: 5578907
MSN Messenger: andrewdmetcalfe at hotmail dot com
AIM: andrewdmetcalfe
Yahoo IM: ametcalf_1999


NewGuy  (B License)

Apr 11, 2002, 12:09 AM
Post #13 of 19 (8150 views)
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Re: Correctly made mini 3-ring riser pictures [In reply to] Can't Post

In reply to:
The greater the gap (arrow) between the top of the harness ring and the bottom of the loop of tape which holds the smallest riser ring, the greater the pull force required to release the riser at high "G's". Picture "B". The shorter the white closing loop (arrow), the greater the chance of damaging your yellow breakaway cable during a hard opening shock, and the higher the release force under high "G's". Picture "C". If your short (right hand) breakaway housing won't stretch "upward" to accept riser stretch during a hard opening shock, you might damage or even "suck through" the yellow breakaway cable, making a cutaway hard or impossible.
Hi Bill,

I'm wondering if I should be worried? Here are the measurements on my rig.

a.) 1/8" Gap between top of harness Ring and bottom of the loop tape. measured by looking from the side (not the front as shown in the photos - from the front it is hard to tell if there is a gap).
b.) 1/4" Gap between outside edge of webbing and where metal housing starts.
c.) 1/4" gap (stretch) between riser grommet and metal housing.

What are reasonable ranges before this is considered dangerous and should be replace? I just bought the rig last fall...

Cheers,
NewGuy Cool



billbooth  (D 3546)

Apr 11, 2002, 7:37 AM
Post #14 of 19 (8105 views)
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Dan;
Measurements "A" and "B" are OK. It bothers me that your short (right) 3-ring housing will not stretch upward to accept opening shock a minimum of 1". That's how much the riser grommet moves upward as the risers stretch during a HARD opening shock. The dimensions you gave me for "B" lead me to believe that measurement "C" is not as bad as you say, unless you have "no stretch" 3-ring housings. Anyway, your risers are OK, and better than most I see. Last year I was at a gear show in Europe, and EVERY riser on EVERY new display rig was far worse than yours. Since the 3-ring release system is a child of mine, I hate to see it corrupted like that, especially because it costs no more to correctly manufacture 3-ring risers than it does to make them incorrectly.
Bill Booth



Premier skydiverek  (C License)

Apr 12, 2002, 1:39 AM
Post #15 of 19 (8025 views)
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Bill,

I know that some companies give you a choice of a 3-rings to be made of standard steel, nickel plated, or stainless steel (http://miragesys.com/product_info/about-g3/hardware.html).

As I assume, the surface of polished stainles steel rings and nickel plated rings is more smooth/slippery than of those made of standard steel . In one issue of Parachutist it was said that a smooth/slippery surface of 3-rings is 'worse' than the one that provides more beneficial friction (like standard steel). Is that true? Out of these 3 options, which is the best (safest) for a 3-ring cutaway system? Are the release forces the same (assuming that all 3 sets - standard, nickel, stainless - are made the same and perfectly, according to your specs). Or it doesn't matter?

Thanks,

Bart



kelly  (C License)

Apr 12, 2002, 10:43 AM
Post #16 of 19 (7984 views)
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thanks for posting safety oriented information like you have.. Its greatly appreciated.
I was wondering, The properly assembled 3 ring configuration seems to be lacking on some of our systems. For those of us who arent jumping highly loaded elipticals is this really an immediate threat that needs to be fixed right away? I jump a spectre 135, loaded at 1:1 My gear is at the dropzone and i did do the checks that you listed above but I think i didnt do it right.. so im not sure if my risers fall into this catagory. I will properly check my gear tomorrow when i get to the dz and make my desicions from there. If they dont measure up to the standards you set then should i get new risers immediately? Im mostly refering to the spacing between the rings and the loop of tape.
thanks
kelly

http://kel197.tripod.com/skydivefriendsTRIPOD/



billbooth  (D 3546)

Apr 12, 2002, 11:02 AM
Post #17 of 19 (7981 views)
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Skydiverek;
You're right. The smoother the surface of the hardware, the less friction. Since 3-rings do not depend primarily on friction, the smoother stainless steel surface lowers their "efficiency" by only about 5%. So this is not a factor in correctly made mini 3-rings. However, if other things are wrong with the construction of your 3-ring, it certainly doesn't help, does it. Electroless nickel plating is the least "slippery", with cadmium somewhere in between.
Where slipperyness (is that a word?) does matter a great deal is in friction adapters, especially your leg strap adapters. Some early attempts to simply make copies of cadmium plated carbon steel adapters out of stainless resulted in adapters that slipped a lot, especially when the webbing gets old or dirty. We just replaced the stainless adapters on a rig made a couple of years ago with 500 jumps on it. They worked fine for a while, then started slipping as the webbing got older and dirtier. New stainless designs slip a lot less, but the jury is still out as to how well they will hold up at 1 or 2 thousand jumps, under all possible conditions. The dirt or sand at different drop zones seems to affect webbing differently. All I can say is, when you buy the latest and greatest, be prepared to be a "test jumper". It is impossible for the manufacturer to test a new product for thousands of jumps, under every possible set of conditions. I hate to say it, but that task, traditionally, has been up to the users. To my knowledge, slipping hardware has never endangered anyone life. It's more of a nuisance than anything else.



TEB6363  (D 16363)

Apr 12, 2002, 11:13 AM
Post #18 of 19 (7972 views)
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In reply to:
If you have a complete "large" 3-ring setup on 1", type 17 risers, then the mechanical advantage of the system is the same as if you were using 1 3/4", type 8 risers. However, if you have a large ring on the harness only, and are using a normal mini 3-ring riser, then you have even less mechanical advantage than if you had a "small" ring on the harness.
Thank you Bill, that was the information I was looking forSmile.

I did not want my mini risers to have "less" of a mechanical advantage, So I had them made with large rings.

From your description of possibilities, it sounds like most skydivers have custom risers of some type.

Thanks for your help Bill.

:::OK, Canopy is Open, No Traffic Around, .. Why are these "Extra" Lines Draping Down??, Damn!


DBTECH  (B 21186)

Apr 12, 2002, 8:38 PM
Post #19 of 19 (7936 views)
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Bill--welcome to the forum ('s)

You should also consider posting on the 'Gear and Rigging' forum--also on Dropzone.com.

Dave Brownell




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