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Calvin19

Interesting pin design

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I found this while repacking a clients' paragliding rescue parachute. I have never seen it before but it's very interesting.

The rig it is on is a front/belly mount container. The deployment handle is mounted on the top, easy access in nasty situations while paragliding and the wing is a ball of shit or twisted up. For those who don't know, paraglider rescue parachutes are just a round parachute that the pilot deploys while still connected to the paraglider (only specialized and newer paraglider kits have cutaway and direct bag deployment systems, but they are not for beginner or even most experienced pilots). If the glider goes out of control, a pilot grabs the reserve handle that is connected to the container closing pin and also connected with the deployment bag. The pilot throws the handle (that is connected to the deployment bag with the parachute inside) away from the glider and once it reaches about a meter away the deployment bag opens and the parachute falls to line stretch and opens. It seem scary to skydivers, but it has a fairly good history of working reliably.

I packed and repacked and tested the deployment a few times hanging, sitting, etc. With this pin it takes an extra few KG of pull force to pull the pin out. Obviously the point of this pin design is to keep the container from opening accidentally from normal use and launching, etc.

I think it has merit. I will CAD a similar design (I have some changes to make that will make it safer for skydiving use), have it CNCd and install it on my skydiving container for the main pin system. It does seem scary, but really is not as scary as it seems the more i think about it. It could save a few accidental container openings.

I doubt it will stick, but it's a cool design and i like new things.

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We, the industry and sport, spent years trying to make pins easier to extract. Went from wire pins that corroded, plated pins that flaked and snagged on the loop, straight pins that bound up, etc. I don't know the relative tightness of the paraglider reserves but considering how tight skydiving mains are and how hard we had to work to decrease the number of PC's in tow somehow it doesn't seem like a good idea.

Inadvertent deployments have always been less.frequent than PC's in tow.
I'm old for my age.
Terry Urban
D-8631
FAA DPRE

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That para-gliding pin makes sense.
It would reduce accidental deployments by creating a minimum pull force.
The key difference between para-gliding reserves and skydiving reserves is that para-gliding reserves lack springs to create minimum pull forces.

Did I ever tall you what a hassle it was to re-close a Russian Air Force Surplus seat pack that had to spring in the pilot-chute and worn-out pack-opening bands?
Hah!
Hah!
Have I ever rambled about obsolete parachutes?
Hah!
Hah!

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piisfish

Don't you think it would chop the loop ?



Obviously the one I make (If I do) will be smooth-edged. Paraglider pins are stamped metal usually and crappy. My personal paraglider reserves (I have 3 harnesses and 4 rescue parachutes) are almost all coated cable closures, way more reliable.


I've never had an accidental pin pop. I just thought the pin was unique. I don't see a need to fix what is not broken, I just thought it was a cool design. Probably not necessary in skydiving with tight pin tension. I paragliding the reserves are usually loose and the pin is held in place with a velcro cover that holds it together.

-SPACE-

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I seems like you are trying to solve a problem that doesn't exist. Before you change the design of a component of a parachute container, don't you think you should run it by the manufacturer? Experimenting with a newly
designed component, (designed by you), is a recipe to create danger for yourself.

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Interesting design. What your missing is that it's not applicable to a hand deployed skydiving pilot chute. First PG reserves tend to be relatively soft pillows in comparison to skydiving mains. It need that bit of security and it only gains a few pounds of force because the you actually have to pull up slack in the loop to release it. I don't think you'll find it that easy on some skydiving rigs. Right now you are just fighting friction and the rigs are tight enough that there is a lot of friction. So the pull force is determined by the tightness of the look. Contrast that with the pull force being dependent on the ability of the loop to move. It's also a hand deploy. You can pull on the damn thing. You've got your hand on the handle and can keep pulling till it opens. And if they are smart they built the container so that the direction that you are pulling on it creates slack in the loop. In other words as you pull it runs through the last flap like a pulley making the loop loosen rather the the other way allowing the tightness of the container to push the flap up against the pin locking it regardless of how hard you pull. Tossing a PC out in to the wind is different. You toss it to the side and it blows back and inflates in the free stream and you get a sharp jerk but then it swings back into the burble and the force drops off. And it can't pull any harder if it get's scaird.

I like playing with weird shit but I'm not wild about this idea. Practice reaching back and grabbing the bridle to pull the pin manually.

Lee
Lee
lee@velocitysportswear.com
www.velocitysportswear.com

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RiggerLee

Practice reaching back and grabbing the bridle to pull the pin manually.

Lee




Truth. :P





I just thought it was an interesting pin/thinking out loud.
I agree there is not a problem with the modern skydive pin. And the more I think about the tension of skydive containers compared to the paraglider reserves I pack I agree it could cause a bigger problem.

Then I think about the sigma main container design and wonder; are there less frequent accidental main bag openings on sigma tandmens? There is that extra safety (bent->curved pin) keeping the main release pin from coming out before the bridal is deployed.

I've seen videos of paraglider reserves coming out on launch, and seen video of skydive containers coming open on climb out and almost bringing down airplanes and helicopters. All from the pin having literally nothing but friction holding it in place.

this old Korean paraglider reserve is the only place I have seen this kind of pin. I'm glad I'm getting feedback on this even though it is mostly negative. Maybe it is more applicable in a pull-out system(that is closer to the paraglider reserve deployment concept)

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RiggerLee

It's also a hand deploy. You can pull on the damn thing. You've got your hand on the handle and can keep pulling till it opens.
Lee



Yep, and I ended up selling the client who owned this funky pin reserve a new harness with a better reserve closing cable (and integrated reserve instead of the belly tumor reserve). She had no idea about the pin design and had never practiced reserve deployments. I did have her try to deploy it and like you said, you're pulling the pin with your hand, not letting a pilot chute do it. I would have no problem/worry using this pin to close my paraglider reserve but it freaked her out.

It's a testament to the importance of people needing to know their gear intimately and not just trusting what someone else sells them.

-SPACE-

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dpreguy

Before you change the design of a component of a parachute container, don't you think you should run it by the manufacturer?


nope.
If I was modifying a harness I would (and I have modified skydive systems quite a bit before[legally] after talking with manufacturers).
Quote

Experimenting with a newly
designed component, (designed by you), is a recipe to create danger for yourself.


I do this for a living. :P
I design parachute parts for anything from tiny UAV reserve parachutes to BASE equipment to reverse engineering 1950s ejection seat parachute components. My other job is selling PG gear and teaching speed flying.
Danger is very relative, and complacency is far bigger a killer than a controlled testing environment where the test pilot/jumper is aware of the situations and potential issues and where appropriate safety systems and backups are in place.

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The goal of providing a mechanism to prevent the pin from coming out is worthwhile.

Better ways that could be devised to keep a pin in place that would be independent of loop tension.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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Interesting. My hang glider belly mount reserve could use those pins. The fairly new reserve and d bag came equipped with two standard curved pins we are all familiar with. The manufacturer told me to fabricate the stows from bungee material kinda like skydiving reserve safety stow material. None of it is TSO'd and actual deployments are slow speed compared to skydiving.


The system isn't as tight as I would like and an accidental deployment would ruin my day especially while being towed. Another solution would be the sheathed cable method mentioned, I am familiar with this on some crew containers.

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VectorBoy

Interesting. My hang glider belly mount reserve could use those pins. The fairly new reserve and d bag came equipped with two standard curved pins we are all familiar with. The manufacturer told me to fabricate the stows from bungee material kinda like skydiving reserve safety stow material. None of it is TSO'd and actual deployments are slow speed compared to skydiving.


The system isn't as tight as I would like and an accidental deployment would ruin my day especially while being towed. Another solution would be the sheathed cable method mentioned, I am familiar with this on some crow containers.



I strongly prefer coated cable with a good 10cm of play, but be sure the handle leash is long enough to extract the cables.

The only way curved pins work for a PG/HG reserve that I am comfortable with is when the area around the grommets and on the pin cover are velcro, so the pin is sandwiched and held in place by velcro, but easily is ripped when you pull on the handle.

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Calvin19

***Don't you think it would chop the loop ?



Obviously the one I make (If I do) will be smooth-edged. Paraglider pins are stamped metal usually and crappy. My personal paraglider reserves (I have 3 harnesses and 4 rescue parachutes) are almost all coated cable closures, way more reliable.


I've never had an accidental pin pop. I just thought the pin was unique. I don't see a need to fix what is not broken, I just thought it was a cool design. Probably not necessary in skydiving with tight pin tension. I paragliding the reserves are usually loose and the pin is held in place with a velcro cover that holds it together.to me that pin shape would make sense on a PG reserve (low tension loop, hand pulled pin) but wouldn't be what I want on a high tension PC pulled pin like in skydiving.
scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

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WARNING, wandering off topic ...

.... I do this for a living. :P
I design parachute parts ... reverse engineering 1950s ejection seat parachute components. ...

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

Reverse engineering is a fascinating process. I have only reverse-engineered an ejection-seat chute from a 1950s-vintage Folland Gnat jet trainer. During the process, we reduced the parts-count ten-fold.
Which systems have you reverse-engineered?

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