PD Reserve Time

[Sled14 0]

I will be getting my container in about a month and have yet to get a reserve. How long would it take to get a 160 sq ft reserve from Performance Designs if they don't have any in stock?

Also, do the same square foot reserves have different pack volumes depending on who makes them? Like, if I put on the container order form that I will have a 160 PD reserve, could a Smart 160 reserve fit fine?

[mjosparky 3]

PD-160R = 388 cu. in.

Smart 160 reserve = 360 cu. in.

My idea of a fair fight is clubbing baby seals

[diablopilot 2]

I'd ask the dealer you're planning on buying it from.

Or *gasp* PD even?

----------------------------------------------
You're not as good as you think you are. Seriously.

[councilman24 36]

To expand on sparky's reply. Manufacturers don't all measure canopy area in the same way and the volume numbers can be different between two canopies of the same brand, model and size by +/- 10%. In general, the PD will pack bigger for a given published area because their area method tends to run small compared to other manufacturer's. Hmmm, don't know what method Aerodyne is using for area, PD, PIA, or something different so I don't know how Smart areas compare to PD areas.

Do NOT try to fit the absolute biggest reserve possible into a container. Because of the variation in volumes it may not fit even though someone else has made one fit. It may not look good, it may be unsafe, it WILL make your rigger mad at you, and it may not go at all.

Pick the appropriate reserve size for you, the appropriate main, and then chose the container size that can comfortablely accomidate them. If your main needs a larger container and it will hold a larger reserve than your minimum then I would recommend you get the larger reserve. Reserves CAN BE too small for a container. Also I don't want you picking a smaller main just because you choose a reserve that needs a container too small for the main you should have.

Pick main model and size, pick reserve model and size, pick container size and if necessary upsize either canopy to accomidate the other. Don't downsize one to accomidate the other.

Seek advice on sizes from your instructors, riggers, and dealers. Don't rely on one entirely on one person. There are differing opinions on what is right for newbies. And don't just choose the answer you like, i.e. "sure you can jump a 120 no matter what that other guy said."

Hmmm, rereading your post it seems your container size is already set. I HOPE that it matches you needs. Above is the way I believe you should chose gear, especially starting out.

Others here have gotten good deals on used containers only to need to set them on a shelf until they're ready for canopies that can fit in it.

I'm really a downer tonight, aren't I?

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

[mjosparky 3]

Quote

Pick main model and size, pick reserve model and size, pick container size and if necessary upsize either canopy to accomidate the other.

As usual Terry’s advice is spot on. I would like to emphasize:

The first thing to do is pick the smallest reserve canopy you feel you want to land when you are unconscious or injured and then go from there.

Remember, bigger is always better when picking a reserve.

My idea of a fair fight is clubbing baby seals

[GravityGirl 0]

Which container did you order?

Short answer. A rig build for a PD160 will fit a Smart 160.

~~~~~~~~~~~~~~~~~
Peace and Blue Skies!
Bonnie ==>Gravity Gear!

[peckerhead 0]

I have a container sized for a 150 and I put a 160 in it.

The bigger the better!

[phoenixlpr 0]

If you check Speed2000 from Paratech.de is packs even smaller, so you might have even bigger.

[billvon 2,406]

>Manufacturers don't all measure canopy area in the same way and
>the volume numbers can be different between two canopies of the
>same brand, model and size by +/- 10%.

I would add that area sizing has the same issues. The PD-126, for example, measures about 137 sq ft per the PIA method, whereas the Precision reserves measure closer to their claimed sizing. So a PD-126 might actually be more comparable to a Micro-Raven 135 than a MR-120. (The PD is slightly larger actually.)

[mjosparky 3]

Quote

>Manufacturers don't all measure canopy area in the same way and
>the volume numbers can be different between two canopies of the
>same brand, model and size by +/- 10%.

I would add that area sizing has the same issues. The PD-126, for example, measures about 137 sq ft per the PIA method, whereas the Precision reserves measure closer to their claimed sizing. So a PD-126 might actually be more comparable to a Micro-Raven 135 than a MR-120. (The PD is slightly larger actually.)

I think thats what Terry just said.

My idea of a fair fight is clubbing baby seals

[JerryBaumchen 1,050]

Hi Terry,

I want to pick your brain a little.

Quote

the volume numbers can be different between two canopies of the same brand, model and size by +/- 10%.

I accept that two sample canopies of the same brand, model & size can vary by 10%.

Therefore, given that) I ask you, if the same sample canopy is measured a number of times (three or more times) with the 'official' tube-device, will the volume number come up the same? Or will they vary? If they vary, any idea on how much might they vary? Try to think seperately for mains and/or reserves.

Or is the problem really only when more than one sample of the canopy is measured?

I am just trying to get some handle on just what is causing this volumetric variation; particularly with reserves. I.e., is it a problem with a variation in the construction/mfg of the canopy or is it a problem with the measuring methods?

There are no wrong answers to these questions.

Thanks,

Jerry

[mjosparky 3]

Quote

is it a problem with a variation in the construction/mfg of the canopy or is it a problem with the measuring methods?

Jerry,

I suspect that both things come into play. Also a different day, a different operator, done at a different location, the variables are endless.

I am sure they must exist but I have never seen written procedures to be used when measuring canopy volume or anything that specifies the equipment to be used.

My idea of a fair fight is clubbing baby seals

[councilman24 36]

Sparky, the written PIA Technical Standard is at http://pia.com/piapubs/TSDocuments/ts-104.pdf

I wrote Jerry a very long answer and it got lost when I hit post!

To tired to rewrite it. The is only one "official" PIA test cylinder for volume. Other exist and other procedures are used. One manufacturer weighs it down and waits as long as it take to stop changing.

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

[councilman24 36]

I wrote a very long reply but it got lost when I hit post.

Too tired to rewrite.

But yes the same canopy will give different results if tested on different days.

But, two individual canopies of the same make, model, size, and options can have significantly different volumes.

There are several other test cylinders around and variations on the procedure (weights, times, diameters, design) used by various manufacturers. Only values determined by Sandy with the PIA cylinder and procedure can really be compared to each other.

See the written PIA Technical Standard at http://pia.com/piapubs/TSDocuments/ts-104.pdf which contains some ancient history on volumen differences.

I rewrite the rest later.

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

[JerryBaumchen 1,050]

Thanks Terry

[JerryBaumchen 1,050]

Hi Sparky,

Quote

Also a different day, a different operator, done at a different location, the variables are endless.

I've spent a good part of my life in test labs and this problem is constant. That is what I am trying to get my hands around; how to eliminate the variables so that the real problems on why there is a variation can be determined.

Otherwise, sizing a container to match a canopy is nothing more than a shot in the dark.

Jerry

[billvon 2,406]

>Otherwise, sizing a container to match a canopy is nothing more than
> a shot in the dark.

Well, any manufacturer can do it empirically i.e. design a container and just try a bunch of reserves. List the ones that fit on their website.

[Cloudi 0]

Quote

Otherwise, sizing a container to match a canopy is nothing more than a shot in the dark.

Thank you for proving a point. Many poeple contact PD about pack volumes, and when we tell them we a) don't measure them and b) let them know we provide canopies to the rig manufacturers instead, they often freak out and think we are trying to hide something from them. The simple fact is, there are too many variables to establishing pack volume, so we don't bother.

The container manufacturer will know what canopy will or won't fit into a given container. Simple as that.

Oh, and to the OP, I believe the expected delivery time for all custom orders is 9-10 weeks. I could be wrong. I'm always the last to know.

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

[riggermick 6]

Quote

>Otherwise, sizing a container to match a canopy is nothing more than
> a shot in the dark.

Well, any manufacturer can do it empirically i.e. design a container and just try a bunch of reserves. List the ones that fit on their website.

That's how I did it, and guess what? That's how everyone else does it and have always done it. There is really no other way to do it, as there are so many variables with components and materials that are inconsistant in their nature. If you build many containers out of sheet metal you will always get a consistant result, if you build many containers (and canopies) out of different types fabrics your results will vary a small amount from product to product. That's the nature of the beast, always has been, always will be.


Mick.


BIG EDIT!!!!



OOOOHH. Did not read the post well enough (got it backwards)!!!!! Manufacturers create a container size based on the most popular models and sizes, they do all of their refinements based on that data. Most other canopies of that ilk will generally fit into the space provided, that's how it's done. Sorry for any confusion.


Mick.

[JerryBaumchen 1,050]

Hi Guys,

Quote

That's how everyone else does it and have always done it

I agree 100% with you.

However, IMO I do not think that that is the best way. Now, with all of the variables in canopy construction, that just might be the best way for now.

I am an engineer, been one for 35 yrs, this makes me want to try to eliminate/control some of these variables. As an engineer, I do not like this situation where a 150 Whizbanger II will vary by 10% or more. I would like to know what is really causing this. And just saying 'Well, that's the way it is.' does not move us forward.

If we wanted to live in a world of 'Well, that is just the way it is.' then we would not 3-rings, etc.

Not trying to be negative towards you two but I would like to have a better understanding of why the 'mystery bulk' thing is still with us after all of these years.

What is it: 'Inquiring minds want to know.'

And I do appreciate your thoughts; something about reasonable people can reasonably disagree.

Jerry

[Cloudi 0]

I agree it would be wonderful to have a consistent measuring system in place. Sometimes, I wonder why it is so difficult. It doesn't seem like it should be.

Then I remember that parachute materials and the parachutes themselves are ultimately made by humans, so inconsistancies will exist. Laser cut pieces are a step in the right direction for reducing these variances, but parachute manufacturers are only one part of the puzzle.

Until the day where parachute materials and the parachutes themselves are made in an assembly line by machines (like cars), I think these variables in production and measuring will always exist. Granted, I don't have an engineering mind, but there's probably a way to reduce these variances before total automation happens. I think the current method of rig manufacturers' sizing the way they currently do is just fine. My rig was made to hold a 190 main and I have yet to find a 190 not fit in it, no matter the make or model.

Of course, rig manufacturers would probably prefer to have reliable measurements available so they don't have to go through this whole sizing process, especially in smaller rigs where crossbrace, etc. comes into play. It's in their court to find the solution if it makes their life easier IMO.

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

[mjosparky 3]

Quote

My rig was made to hold a 190 main and I have yet to find a 190 not fit in it, no matter the make or model.

How much difference is there between a 190 nine cell and a 190 seven cell? Or a 7 cell made of ZP and a 9 cell made of F-111? How about a hybrid?

A lot of the variables could be eliminated if the manufactures would just use the same base line to begin with. They can’t even agree on how to measure the area of a canopy.

My idea of a fair fight is clubbing baby seals

[Sled14 0]

I ordered a Wings with the reserve sized for a PD 160. Of course I listen to all their advise its just that this summer I'm really busy and out of state for summer break from school so I'm not able to get to the dropzone that often.

[councilman24 36]

Jerry,

I think your chasing a rainbow. We still have to try on pants to see if they really fit. Even each individual pair of jeans. Same thing.

Starting with the art of fabric finishing, shrinkage due to stitching, etc. etc. I don't think your going to get your wish. That's what the French wanted. A hard and fast list that yes this is compatible and no this isn't. It was soundly rejected by everybody else in the room, not just americans.

Atair's non-woven fabric R&D with "welded" instead of stitched seams might get you closer. But even then variations in packing may very well lead to differences in packed volume.

This isn't a hard science. For some of the same reasons we get lemon canopies from time to time. I had a Sabre 190 that PD never could stop from spinning on opening with the brakes set. They made it right. I'm sure they'd like to eliminate variation also.

What issue is it that you think is a problem? For the most part, if customers follow manufacturer's advice and don't push the limts, things go together pretty well. It might be nice if we didn't have to wonder and curse the cutomers putting a "350 cu.in." canopy in a "340 cu.in." container, but then who would we bitch at?

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

[JerryBaumchen 1,050]

Hi Cloudi & Terry,

Cloudi) I would be a happy camper if PD would put out some numbers on volume. I had a hour long telecon with John LeBlanc back in Jan and the one thing is sure; PD will NOT give anyone any numbers on volume. Read that as: NONE.

I could live with some numbers even if the infamouse 150 Whizbanger II was listed as being between 375 cu in & 405 cu in. But PD will not.

Terry) I order all of my bluejeans from Lands End. I give them the waist & the inseam. I have never had a pair that did not fit. Would you accept two pair of jeans where you tried on one pair at X waist & Y inseam and it fit, but when you got home the 2nd pair were 3" longer in the inseam? I know that I would return them.

Now who wants return their 150 Whizbanger II when you have waited 10 weeks for that custom-colored sweety but it just is 'really' tight when you pack it into your brand new SlimTrim container?

I have a friend (he's been jumping for 35 yrs, 2000 jumps) who just bought a brand new rig. He specified the canopies (main & reserve) in detail. Every pack job he struggles to get the main closed, it is simply (IMO) too tight. Yet he did everything that is now considered OK in this parachute equipment world. Also, after assembling and packing his reserve (very tight) I told him to never bring it back to me again.

Try to understand, I am just trying to get a grip on this continuing problem.

I may never get any farther along than where we are currently at but I would like to take a stab at.

As I indicated, I could live with any numbers as long as they came from the canopy mfrs themselves.

Thanks,

Jerry