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crapflinger2000

Reserve PCs - fabric in or out

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Guys, I am completely out of the rigging game (and skydiving as well) but have been thinking bout this stuff a lot lately.

Since this forum seems like a good way to get some questions answered I always wondered about, here is one...

What are the mechanics involved when the mfr decides if fabric should be in or out of the coils of a PC?

I mean, I always followed mfr instructions and "did as I was told", but never quite understood the rationale.

I am aware that tapered/non-tapered coils (i.e. Talon vs Vector) might require different treatments of the fabric to combat coil lock, but even within the tapered PC rigs there was different guidance from mfr to mfr...

Forgive me if I get some of these wrong, its been years...

Racer - fabric in
Javelin - fabric out
Talon 1&2 - fabric in

So, philosophically speaking, whats the thinking behind preventing coil lock?

If this goes well, maybe I will start asking some of the "not sure why but the manual says... " questions I always had about rounds.

__________________________________________________
What would Vic Mackey do?

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Holy crap ... flinger2000, It's been a long time.

I've wondered the same thing on occasion. After my own experience, I tend to do "mostly" what the manual says but will devieate every so slightly if they're just doing things different, to be different.

Good luck on your quest.
My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

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I will speak for the Racer = Fabric in.
Did you ever stand on the end of your necktie and try to stand up straight?
I have seen pilot chute springs fail to extend because the canopy fabric was tightly tucked under the spring base.
I have seen it both in Free fall and on the table.

John

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PLUS if it's out on The Racer it looks so yucky, all flapping around in the wind like that ;) - I have a few Centaurus accuracy rigs in my care and packed a few without a manual (because the manufacturer didn't have one) and left the fabric out. Then I got a "word" file of the manual and packed the rest fabric in as per the manual..... when they came for repack and I deployed them on the ground there wasn't any difference........

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Good question. It's one of those design decisions that isn't always clear to riggers.

The Racer has the fabric IN because there's no other place to put it. One pin pop-top style rigs, the Reflex and Teardrop, have cupped caps wider than the spring so there's space to stow the fabric under the cap but OUT of the spring.

I generally like the idea of not having the fabric rubbed on between coils. Javelin keeps it OUT, although a bit may be between the coils at the coil top due to tensioning the fabric for all the twisty stuff done with it towards the bottom of the rig.

(That's another funny thing about rigging pilot chutes: In some cases a company wants them packed neatly to open quickly and symmetrically, while in other cases one can twist and mangle the pilot chute since it isn't supposed to matter much.)

Then there's the Wings, where fabric could be kept out but it is put IN -- rather an inconvenience for a rig where it is so tough to get the pilot chute to seat down tight.

I just went and played with a Wings PC. Compressing it on a hard surface, fabric OUT it is about 2.4 cm thick, but fabric IN I typically get about 3.3 cm. That's 1.1 cm thicker, or around 0.45 inches. While those numbers may change with how one measures (I did it quickly) and how the fabric is packed in the coils, it does show how much more compact it would be if one didn't have to jam the fabric between the coils.

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Two factors determine where you stuff fabric and mesh.
The first variable is the spring configuration. Cylindrical springs (Talon, Flexon, Voodoo, Telesis, Strong tandem, etc.) need fabric - and mesh - stuffed in between the spring coils to prevent coil lock.

Since conical springs (MA-1, Racer, Vector 2 and 3, Javelin, etc.) are far less likely (bordering on zero) to coil lock, fabric can be stuffed any where it looks pretty ... except under the base of the spring.

The second variable is appearance. When pilot chute caps are exposed (Race, Reflex, Javelin, Wings, etc.) riggers need to stuff fabric deep enough that it cannot be seen, faded by sunlight or dragged through the weeds. Then the rigger has to stuff fabric deep enough to prevent it from working loose over the next 180 days (nudge!, nudge!, wink!, wink!, say no more!, say no more! ...).

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Quote

Two factors determine where you stuff fabric and mesh.
The first variable is the spring configuration. Cylindrical springs (Talon, Flexon, Voodoo, Telesis, Strong tandem, etc.) need fabric - and mesh - stuffed in between the spring coils to prevent coil lock.



Thanks [to all respondents BTW]!

I thought the Talon PCs were conical as well? Maybe it was just some of them. I seem to recall they were a very long (relative to the Javelin and Racer PCs) conical design...

OK, I guess I can move onto my round parachute question(s) in a new thread.

__________________________________________________
What would Vic Mackey do?

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"
Quote

... I thought the Talon PCs were conical as well? Maybe it was just some of them. I seem to recall they were a very long (relative to the Javelin and Racer PCs) conical design...

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"

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

If you want to be picky ... Strong springs (Grabber, etc.) are almost cylindrical. They have a slight "hour-glass" shape, making them slightly smaller in diameter in the middle.

During the years (1994 to 1997) I worked at Rigging Innovations, I only saw one Talon spring coil-lock. That was packed by some-one outside the factory and we doubted if he followed the manual.

Like Sandy Reid used to say: "If you don't understand something, copy it exactly."

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