Pack Volume - Sabre170

[Mac 1]

I have tried looking around, but I am unable to find the pack volume of a sabre (old sabre) 170.... anyone know where this data can be found? (or know what it is?)

Thanks for any help

Michael

[IanHarrop 42]

Check here:

http://www.dropzone.com/files/archive/gear/Canopy_vols.html

"Where troubles melt like lemon drops, away above the chimney tops, that's where you'll find me" Dorothy

[Slurp56 0]

apparently it grew as time went on. Its listed 3 times.

________________________________________
I have proof-read this post 500 times, but I guarantee you'll still manage to find a flaw.

[JerryBaumchen 1,415]

There is a good possibility that those were the three actual measurements.

PD will not give any volume numbers for their canopies. Me thinks because they vary so much. I am thinking that the biggest variable is the z-p fabric, which they have little control over.
I know of one rig maker who built a rig for a customer with a demo PD canopy and then when his new exact version of the same canopy arrived it was too big for the now finished container. The rig maker had to make an entire new rig for the customer.

Jerry

[Cloudi 0]

  Quote

PD will not give any volume numbers for their canopies.

I'm sure you already know this, but for the information of others: This is mostly because PD hasn't wasted their time trying to measure something that no one can agree on with a consistent, reliable method of measuring. The same person can use the same technique 3 times in a row on the same day in the same environment and end up with 3 different results. Current methods (PIA proposed or otherwise) are not consistent, so why bother?

PD provides canopies to container manufacturers for sizing instead. It is up to that manufacturer to realize a variance for line types, environment (humidity or lack thereof), packing technique, and canopy age/condition (older/more used = slightly easier packing).

That's why the best source for learning what canopy will fit into what container is still the rig manufacturer, not a chart that someone (although well intended, I'm sure) put together.

Stepping off soapbox now...

Kim
Watch as I attempt, with no slight of hand, to apply logic and reason.

[councilman24 37]

As big a variable as the measurement is the actual size of the canopy. Canopies can vary up to 10% from one individual to another. Not due to measurement but due to actual volume. Both minor construction variables from sewing and variables in volume of materials lead to this. This is why buying a canopy at the absolute top end of the container size is dangerous. It may not fit. I try to keep my rigging customers from trying doing this on reserves.

One person, using one apparatus, using consistent technique, and measuring with consistent environmental conditions can get reasonably reproducible and comparable measurements. That doesn't mean someone else wouldn't get a different measurement with the same canopy. Or that that number would be comparable to quoted sizes of containers.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[JerryBaumchen 1,415]

Hi Terry,

Bravo!!!!!

A canopy that is at the top end of the container size will just wear you out packing it over and over. Now of course if you use packers, so what.

If it's a reserve you (the rigger) are stressing things too much (IMO), the grommets, the locking loop, etc. Also, we are now experiencing damage to AAD cutters from too much pressure between the grommets; this problem can exist anywhere that the cutter is placed, including on top of the pilot chute. Well, probably not on pop-top type of containers; the exception that makes the rule.

Mike Truffer did an editorial in SKYDIVING a few years ago in which he recommended buying containers (main & reserve) one size larger than the canopies you intend to put into them. Just to deal with these things.

This will make it easier for the jumper in packing his main, the rigger in packing the reserve, and (hopefully) less chance of damage to the rig itself.

I recently assembled and did a first-pack-job a new rig with a reserve canopy the owner had owned for a number of years. The previous rig the reserve canopy was in was a Javelin and the metal plate in the bottom of the pack tray was seriously bent from the forces used in packing this too large canopy (again IMO) into the reserve container. When I finished I told the customer not to ever bring back to me again. Simply too much work for too little money (once again IMO).

I'll get down off of my soapbox now,

Jerry

[councilman24 37]

Hey Jerry,

I had a parapak Javelin with a reserve that was supposed to fit. I got it in there but the container was drum head tight. We finally decided that it didn't fit, the canopy and been spec'ed on the container order, so it was sent back for the right size.

I don't know about one size too big. I had a guy with a 170 reserve in a J5. It wasn't safe. There was no tension on the safety stow. (I know, this is more than one size too big) I wouldn't pack it. Another rigger with 30 years experience but limited square experience packed it but told the guy he wouldn't again. Then another fairly new rigger packed it routinely. Both were informed about my opinion. THEN the guy became a rigger so he could pack it himself. THEN, EVEN WORSE, he sold it to a newbie. The newbie called me, told me what rig it was. I had to tell him I wouldn't pack it and why.

As long as one size bigger still has that reserve in it's specified range, then fine. We get to do an easier job and look good doing it.
My last custom rig was ordered with the canopies specified. When I put the reserve in the free bag I could pinch about 3 inches of extra fabric between my two fingers. Went back and a replacement was in my hands in 8 days from the initial call. (Thanks Mick)

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[mjosparky 4]

445, 451, 397 sq. ft. Take your pick.

My idea of a fair fight is clubbing baby seals

[Cloudi 0]

  Quote

As big a variable as the measurement is the actual size of the canopy. Canopies can vary up to 10% from one individual to another. Not due to measurement but due to actual volume.

Absolutely!

I'm not trying to "blame" the method, so much as I am trying to explain that numbers don't mean squat when you're trying to fit a xxx cu. in. canopy into a xxx cu. in pack tray and it doesn't fit. Numbers don't make it fit just because someone said it "should" because of information they got from a pack volume chart.

You obviously know more about all this than I do from experience. I'm pointing out what I know from other experienced individuals who design and make the canopies. They are or were riggers themselves.

If I've been misled in my understanding of the futility of measuring pack volume for overall use, I'll happily grovel at your feet and bow to your wisdom.
Thanks for going easy on me.

Kim
Watch as I attempt, with no slight of hand, to apply logic and reason.

[councilman24 37]

Not ragging on you. Only pointing out that two of the same canopy REALLY ARE different in size.

Unfortunately, while PIA spec'd a method, and all of the "PIA" measurements have been done with one apparatus and by one person, other PIA members (at least three) have built their own varying apparatus and use their own method.

Another member has tried to develope a method to measure container volumes. He had thoughts of inflatable bag shaped bladders. Never got anywhere that I know of.

Experience with real canopy/container combinations is still the best predictor.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE