Forums: Skydiving: Gear and Rigging:
Main closing pin position

 


reyno_gr  (C License)

Apr 9, 2005, 3:43 AM
Post #1 of 16 (3468 views)
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Main closing pin position Can't Post

Everyone of the people I watch pack slide the main (curved) pin into the container closing loop as far it'll go (i.e the 'eye' of the pin is effectively touching the closing loop). I over heard an experienced skydiver tell a newbie that this was incorrect and the closing loop should sit halfway along the pin. Does it really make that much difference? And doesn't the former reduce the likelyhood of a premature deployment though the pin being inadvertantly knocked out?
Views please.


riggerrob  (D 14840)

Apr 9, 2005, 8:58 AM
Post #2 of 16 (3365 views)
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Re: [reyno_gr] Main closing pin position [In reply to] Can't Post

We prefer inserting curved pins 2/3 of the length of the shank.


reyno_gr  (C License)

Apr 9, 2005, 9:11 AM
Post #3 of 16 (3358 views)
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Re: [riggerrob] Main closing pin position [In reply to] Can't Post

Riggerrob. Thanks for the response... with all the views and no responses I was beginning to think it either doesn't matter, or no one knew the answer. Why is 2/3 prefered? What are the down sides (if any) in putting the pin into the closing loop up to the 'eye?


tbrown  (D 6533)

Apr 9, 2005, 9:57 AM
Post #4 of 16 (3344 views)
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Re: [reyno_gr] Main closing pin position [In reply to] Can't Post

In reply to:
Riggerrob. Thanks for the response... with all the views and no responses I was beginning to think it either doesn't matter, or no one knew the answer. Why is 2/3 prefered? What are the down sides (if any) in putting the pin into the closing loop up to the 'eye?

In particular, isn't it equally important to keep the "eye" clear of the grommet ?


tdog  (D 28800)

Apr 10, 2005, 3:27 AM
Post #5 of 16 (3255 views)
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Re: [reyno_gr] Main closing pin position [In reply to] Can't Post

I went to the Vector III manual - thinking that the owners manual would be the best place for this answer.

The manual specifies insertion from right to left (I assume since the bridal is stored on the right, that way it pulls it out in the natural direction).

The manual does not specify how far to insert it, but the attached picture cut and pasted from the manual shows full insertion.

The manual says: 6. Insert the closing pin (located on the bridle) through the closing loop from right to left.

Ideas? Thoughts? Bill or any other manufacture out there?

I personally insert from right to left, nearly all the way it naturally wants to go, with a smiley face. But then I spin it 45 to 90 degrees so the loop of the pin is somewhat down, and the pointy end is somewhat up. I have been told that this orientation is safer, as if you brush your rig on the bench as you sit down, the pin is likely to be pushed in farther, not pushed out
Attachments: Vector Pin from Manual.JPG (23.1 KB)


reyno_gr  (C License)

Apr 10, 2005, 10:43 AM
Post #6 of 16 (3211 views)
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Re: [tdog] Main closing pin position [In reply to] Can't Post

Tdog your explai#nation is the way I place my pin. I suspect having the pin inserted right to left is far more important than whether is 1/2, 2/3 or fully inserted into the closing loop. Judging by the low number of responses I guess it's not that big a deal how far it's inserted (as long as its secure enough to do its job). Maybe the 'experienced' jumper that led me to pose this question was just a wannabe skygod trying to impress a newbie?


mnealtx  (B 30496)

Apr 10, 2005, 11:43 AM
Post #7 of 16 (3196 views)
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Re: [reyno_gr] Main closing pin position [In reply to] Can't Post

I seem to recall seeing something about keeping the eyelet clear of the grommet.

It makes sense, as I think about it:

One way to check would be this:
Extract the pilot chute and pull the bridle out. I'm guessing (since I don't have my rig here to do it) that the force applied by the bridle would "stand up" the pin in the closing loop before it extracts it. If the eyelet is against the grommet when that happens, I could see how it could wear against the closing pin and grommet both, possibly causing rough edges or even damage to the pin attachment to the bridle.

Can someone give this a shot, and let me know if I'm completely off base or not?


Martini  (D 23756)

Apr 10, 2005, 7:32 PM
Post #8 of 16 (3149 views)
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Re: [mnealtx] Main closing pin position [In reply to] Can't Post

I haven't seen or heard of top flap grommet damage due to closing pin wear. Inserting the pin all the way might help keep it from coming out by accident as compared to partial insertion. Eye down/tip up could help keep the pin in if you sit on something that pushes on it but it could work the other way if you snag something while standing up or the like. Pin orientation as regards bridle pull is moot if you're falling straight down, if you throw with forward movement the logical pin orientation is eye down. My opinion only, open as usual to disregard or disagreement.


mwilson-roberts  (C 100965)

Apr 11, 2005, 1:38 AM
Post #9 of 16 (3121 views)
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Re: [reyno_gr] Main closing pin position [In reply to] Can't Post

I was told the exact same thing from a rigger at a boogie once....
what they were trying to tell me was that its ok to put the pin in all the way but if you look very very close at the pin, the final 1mm just before the eye, the pin gets ever so slightly wider, we are talking not a lot in all of this. Its ok to put the pin all the way home but the rigger was trying to tell me not to force it home so much that the loop is jammed hard against the eye thus sitting on the ever so slightly wider portion.
Does that make sense?


rsibbald  (C 103410)

Apr 11, 2005, 7:25 AM
Post #10 of 16 (3066 views)
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Re: [reyno_gr] Main closing pin position [In reply to] Can't Post

Several riggers have recommended to me to push it around 2/3 of the way in, on the grounds of reducing the risk of premature deployment when moving around in the aircraft.

On properly sized (main/container/person/closing loop) rigs, this is not normally an issue. However, there are several configurations I have seen where if the pin is pushed all the way in, the tension of the closing loop or a badly packed main, can cause the pin to rotate on itself and point outwards from the rig. This can slowly work its way loose when compared with a normal flat pin configuration.


(This post was edited by rsibbald on Apr 11, 2005, 7:26 AM)


yoink

Apr 11, 2005, 8:04 AM
Post #11 of 16 (3048 views)
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Re: [riggerrob] Main closing pin position [In reply to] Can't Post

Wasn't there a post & pic on here a while ago that showed a mal caused by the eye of the pin sliding through the closing loop entirely?

The guy pitched the PC and got an instant PC-in-tow...

or did I dream that? CrazyLaughLaugh


hectech  (B 6568)

Jun 25, 2013, 8:30 AM
Post #12 of 16 (2433 views)
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Re: [mnealtx] Main closing pin position [In reply to] Can't Post

Another way to think about this: consider why we don't use straight closing pins. If the pilot chute deploys as intended, a straight pin would not pull out because the pull would be perpendicular to the pin. With a curved pin that's not a problem, because it will rotate to stand up then slide out of the closing loop - unless the eyelet is on the grommet. If the eyelet is on the grommet, the tension on the bridle might not be sufficient to make the pin stand up so it can slide out of the loop. You would then have a pilot chute in tow. If the eyelet is just off the grommet, i.e., pin inserted 1/2 to 2/3 into the loop, the eyelet can turn when pulled because the fabric will deform on the side of the eyelet opposite to the bridle to allow the rotation, unlike the grommet which is not compressible or easily deformable.


JohnMitchell  (D 6462)

Jun 25, 2013, 8:45 AM
Post #13 of 16 (2408 views)
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Re: [mnealtx] Main closing pin position [In reply to] Can't Post

mnealtx wrote:

I'm guessing (since I don't have my rig here to do it) that the force applied by the bridle would "stand up" the pin in the closing loop before it extracts it.
Long ago, on rigs that had closing flaps small enough for the end of the pin to hang off, there were a few pilot chute in tow mals because of that.


erdnarob  (D 364)

Jun 28, 2013, 1:10 PM
Post #14 of 16 (2063 views)
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Re: [reyno_gr] Main closing pin position [In reply to] Can't Post

Have a look on the picture included. This is what is "recommended". Personnaly I prefer to set up the curved pin a bit further by having the closing loop at the very beginning of the flared part of the pin toward the eyelet, indicated by the red arrow. When the briddle is pulled by the pilot chute, it goes vertically and starts to pull the curved pin. Because of the slight leverage (distance between the closing loop and the briddle attachment) the pin changes for a vertical plane (no more flat on the container). That provides the briddle with a easy way to extract the pin. You can try it yourself on the ground by pulling slowly the briddle vertically while the rig is flat. Observe the pin change of plane. Repeat with different closing loop positions.
Remember that a premature opening of the main container at the wrong time is one of the worst scenario


(This post was edited by erdnarob on Jun 28, 2013, 1:14 PM)
Attachments: Main pin set up.png (67.8 KB)


RiggerLee

Jun 28, 2013, 2:03 PM
Post #15 of 16 (1940 views)
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Re: [erdnarob] Main closing pin position [In reply to] Can't Post

Actually there can be problems with curved pins. I posted something about this on base jumper....

http://www.basejumper.com/cgi-bin/forum/gforum.cgi?do=post_view_flat;post=2964578;page=4;sb=post_latest_reply;so=ASC;mh=25;

It was a comment in relation to a towed PC. The main descusion is about pin cover flap design. I also posted some pictures of bent pins, I think they are on the next page.

Lee


airtwardo  (D License)

Jun 28, 2013, 5:30 PM
Post #16 of 16 (1772 views)
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Re: [RiggerLee] Main closing pin position [In reply to] Can't Post

RiggerLee wrote:
Actually there can be problems with curved pins. I posted something about this on base jumper....

http://www.basejumper.com/..._reply;so=ASC;mh=25;

It was a comment in relation to a towed PC. The main descusion is about pin cover flap design. I also posted some pictures of bent pins, I think they are on the next page.

Lee

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