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mjosparky

Slow openings?

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the first thing i do to speed up the opening on any canopy is to reduce the tension on the line stows. going more for ten pound tension to release each stow rather than fourteen. that's what works for me, your milage may vary.


pulling is cool. keep it in the skin.
options: it does a body good.

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I have. When I bought my spectre in 1999, I tried every packing trick imaginable to speed up the openings (not quartering the slider, not rolling the tail, etc.) and had no success until I called PD and got a smaller slider. With the smaller slider, I never had excessive snivel nor a hard opening in about 300 jumps on the canopy. The person I sold the canopy to had no complaints either.

Then again, I know who you are asking for, and I told him that on Sunday. Also, did you fix that pop-top yet?B|
________________________________________________________
Abbie drove me to Idaho and all I got was this lousy sigline

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I have. When I bought my spectre in 1999, I tried every packing trick imaginable to speed up the openings (not quartering the slider, not rolling the tail, etc.) and had no success until I called PD and got a smaller slider. With the smaller slider, I never had excessive snivel nor a hard opening in about 300 jumps on the canopy. The person I sold the canopy to had no complaints either.

Then again, I know who you are asking for, and I told him that on Sunday. Also, did you fix that pop-top yet?B|



PD said they do not have a smaller slider for the Spectre 170. So no exchange. I am going to try and buy the next smaller size they have which is 20" x 31". The one on it now is 30" x 23". What size were you jumping and what size slider did you go to?

It seems I am fixing that pop top about every 20 minutes.:P

Sparky
My idea of a fair fight is clubbing baby seals

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the first thing i do to speed up the opening on any canopy is to reduce the tension on the line stows. going more for ten pound tension to release each stow rather than fourteen. that's what works for me, your milage may vary.



How can stows affect the speed of the deployment? The canopy is still in the bag until after the stows have released. Stows may change the time to line stretch but have no affect on deployment.

Sparky
My idea of a fair fight is clubbing baby seals

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the first thing i do to speed up the opening on any canopy is to reduce the tension on the line stows. going more for ten pound tension to release each stow rather than fourteen. that's what works for me, your milage may vary.



How can stows affect the speed of the deployment? The canopy is still in the bag until after the stows have released. Stows may change the time to line stretch but have no affect on deployment.

Sparky



I believe tighter stows mean there will be more continuous tension on the lines during deployment, as opposed to having having loose stows, which could dump the lines out too fast, and end up hitting you hard when your weight catches all at once.

However, I wouldn't intentionally do this as a way of speeding up the deployment.


If you want to speed up the deployment:


Don't bury or roll the nose, leave it exposed. The further it is out, the faster the opening.
When quartering the slider, pull it toward the tail of the canopy moreso than the front.
When rolling the tail, don't roll it so far, and don't roll it so tight.
__________________________________________________
I started skydiving for the money and the chicks. Oh, wait.

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Snatch force: The shock produced on the load when then parachute assembly fully strings out and becomes suddenly accelerated to th same speed as the load. (from pointers

Tighter line tension will result in a lower snatch. p.466 of poynters has a graph that illustrates how the snatch affect opening shock. Basically, the lower the tension, the higher the snatch, the quicker the opening shock.

Note: Snatch is usually what makes the opening smack you, not opening shock. Ask anyone who's had line dump!:P
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

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I had a spectre 120, but since it was so long ago I don't have the slider dimensions. I do remeber it was the same width and a couple inches less front to back. I find it hard to believe PD doesn't have an answer for you. I've had smaller sliders on both my spectre and velocity that I got from PD. Maybe you just weren't talking to the right person there?

As far as the reflex goes, maybe someone familar with the tricks for packing them can help you out. Riggermick should be willing to give you some pointers, because done right the closing loop should not need constant adjustment. I've seen a couple different riggers bend pins on a reflex from over-tighening, so watch your pull force. Of course, it could just be something as simple as silicone on the closing loopB|
________________________________________________________
Abbie drove me to Idaho and all I got was this lousy sigline

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Deployment does not happen until after the canopy comes out of the bag. Snatch force is dependent on the differential in speed of the bagged canopy and the load at line stretch. Opening shock is dependent on fill time and slider size and design.



As far a "line dump" goes, if there is such a thing it would happen every time a reserve was fired. They only use 2 locking stows. The locking stows keep the canopy in the bag and prevent the start of deployment until line stretch is reached. Other stows if used keep the lines playing out neat and orderly and to some degree contribute to bag whip. Jmo

Sparky
My idea of a fair fight is clubbing baby seals

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Deployment is actually the time from pack opening to line stretch prior to inflation.

Opening shock is the force applied to decellerate the load. and is also dependent on the speed of the load and slack on the line (line dump).
Loose bands = increased bag decelleration = increased snatch.

I have seen data from several jumps and the snatch and opening have very distinct peaks. Snatch can be harder than opening shock.

As for line dump with freebags, well, yes it does happen. A deployment like that can create an 80%-20% load on the riser.

Inspect your MLWs for nicks on the selvage!

One company has fixed thier freebag.
Still waiting for the rest.
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

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Why would people even think of rolling the nose on a spectre? There's no reason to. The spectre already has slow enough openings and rolling the nose of the canopy seems to have went out as technology improved. On most modern canopies, you can just let the nose lay...which is the way it should be anyway rather than having the opening forces due to the packjob. Rigging errors happen...and packing a main gives lots of people lots of chances to screw up.


Cheers,
Travis

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... reflex ... Of course, it could just be something as simple as silicone on the closing loopB|



>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Bad idea.
Manuals specifically forbid applying silicone lubricant to the adjustable closing loops installed in Reflex, Racer and Teardrop serves.
ANY silicone is liable to wick up the closing loop and allow the adjustable loop to slip.
Thanks to Iron Mike, I learned that the key to making Reflexes, etc. look pretty is canopy distribution. The less canopy bulk under the base of the pilot chute, the prettier it looks.
If you ignore canopy bulk distribution, no amount of jerking on the adjustable loop - after the fact - will make a Reflex, Racer or Teardrop look pretty.

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I am gonna call Shananagins on this one too. Maybe on older canopy designs ( I dont know why) but I have jumped the same canopy with and without line stows (except the grommets of course ;) ) and have felt no diference. The snatch force is a characteristic of the canopy, not the line stows.

As long as the lines are deployed evenly, the canopy should open the same. You can do this via rubberbands, line pocket or coil of death. I like packing the coil of death for people while they are looking on in horror!!!

Johnny
--"This ain't no book club, we're all gonna die!"
Mike Rome

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Wear a 8" Cabar and strech your arms out the next time you pack it. Make sure that your canopy sees your serious knife. Then get down and say just load enough for just your canopy to hear, you don't want to embarres her, " Listen you snivily ol' rag if you don't get with the program real soon I'm going to cut you up into strips roll and sell them as trendy toilet wipe and use your lines for boot laces that I'll give to the salvation army.

Now I don't know if this will work for you but if you go that far at least she will know your very serious bout opening with some degree of urgency.

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The snatch force is a characteristic of the canopy, not the line stows.



Not with line stoes? I'll call shananagins on that. Total absolute and complete shananigans
Here's the definition.
"Snatch force-The shock produced on the load when the parachute assembly fully strings out and becomes suddenly accelerated to the same speed as the load. Comes prior to opening shock."

The canopy is just a one part of the equation. A large part of what determines snatch is the speed of the assembly prior to excelleration. Clearly tight elastics will slow the decelleration prior to line stretch.

Here's the equation: snatch force=delta speed/time.
There are two ways to reduce snatch.
1. decrease the delta speed
2. increase the time

Decreasing the delta speed is achieved by slowing the bag's decelleration off the back.
Increasing the time is achieved through various means (packing, canopy design)

I believe you may have confused snatch force with opening shock. That is very dependent on the canopy and is the second part of the process.
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

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The reason to inspect your selvage edges is that an uneven deployment can result is an 80-20 load on your harness. a damaged selvage edge weakens the webbing.

Although main deployments are usally orderly, a reserve deployment is not always. (for example a streamer can put you is a wacky body position with providing decelleration.)

If you have student gear, this can become even more critical.
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

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