PSI in a Mag's dump chamber?

[Pneumagger]

this may be a question for some of the more tech savvy mambers, but I would like to go about finding the pressures in a mag's dump chamber. Ideally, I eventually have to experimentally find it's pressure. Furthermore, I'll need it's pressure before a shot, and after a shot - and it'd be stellar if I could derive a relationship between pressure changes effecting velocity.

I realize there are many factors that effect the dump chamber pressure like bolt, particular valve model (Classic, RT, X), and Velocity.

To simplify my measurements, I am in search of a method to obtain the following numbers:

• Dump Pressure of a Level 7 Classic Valve @ 300fps before the shot.

• Dump Pressure of a Level 7 Classic Valve @ 300fps after the shot (residual pressure).

• Dump Pressure of a Level 7 X Valve @ 300fps before the shot.

• Dump Pressure of a Level 7 X Valve @ 300fps after the shot (residual pressure).

• Classic Valve dump chamber volume with Level 7 installed.

• X Valve dump chamber volume with Level 7 installed.

Although it is not difficult to obtain these pressure values directly in an experimental setup, I have a doubt there's enough meat in the side of a valve to just start tapping hoses into for measurement. Is there a simpler (safer) way to measure these values other than tapping a pressure sensor into the side? Also, I don't mind sacrificing a classic valve for this - but retrovalves are darn expensive.

[y0da900]

There is enough meat there to tap in. If there wasn't, then the Smart Parts magic box would tear out through the wall when they were installed.

http://www.network54.com/Forum/9013/message/1171336010/picture+from+Tyger

[Shane-O-Mac]

Yep around, 400-450 is what I have been told. You can tap into the chamber like the "Magic Box", just remember, most paintball gauges are not actually gauges. They are Indicators, as they are not as accurate as people think they are. even 2 guages from te same batch can be as much as 50-100psi different. Seen it myself, or I wouldnt have beleived it. So if you actually do a gauge on the chamber, research and buy the proper equipment. Preferably a transducer and computer, similar to what they test regs with. search for "Have Blue" he posted lots of reg testing results, and at one time listed how his test rig was made.

question is though, why do you want this info....................hmmmmmmmm?

[Pneumagger]

I'm sure I could dig up enough info on the internet to get what I need. But to design a new valve for my senior project, I need to accurately document and actively find the pressures of older model valves for myself.

Plus, I'm much more comfortable working with data I obtain myself than data given to me over the internet.

edit - as far as instrumentation, I'll be using a lab grade setup at my unversity, so I should be fine. I really don't want to scrap a Valve learning the hard way though. So suggestions from knowledgeable people would be highly valued.

[y0da900]

Nicad did a very similar experiment on an Ion before, you might want to see where he could steer you. Not sure of the best way to reach him, but he usually responds quickly enough where this link goes.

http://tinkersguild.org/phpBB2/viewtopic.php?t=545

[Ydna]

I don't think you'd have to use a pressure transducer to get a reasonably accurate reading. I mean, it'd be super accurate, but maybe overkill. If I were doing it I'd just get a large-dial gauge, such as one of those 2" ashcroft gauges (or larger) and use that. Hopefully you could find one tapped smaller than 1/8" NPT since a smaller thread would probably be easier to install in there.

I think if I were doing it, I'd make a new "dump chamber" tester piece to attach to the rest of the valve like the actual dump chamber does. Then just tap it for a guage. Chrono the gun then take the dump chamber off and put on the testing setup, air it up and you've got your reading. You can repeat that with the other valves as needed (as long as the parts were compatible). The reason I like that route is because it wouldn't require any permanent modifiction to the functional parts.

It's the type of info that would be useful for somebody making a reg-less mag valve modifiction (ie. me) lol

[CaliMagFan]

this may be a question for some of the more tech savvy mambers, but I would like to go about finding the pressures in a mag's dump chamber. Ideally, I eventually have to experimentally find it's pressure. Furthermore, I'll need it's pressure before a shot, and after a shot - and it'd be stellar if I could derive a relationship between pressure changes effecting velocity.

I realize there are many factors that effect the dump chamber pressure like bolt, particular valve model (Classic, RT, X), and Velocity.

To simplify my measurements, I am in search of a method to obtain the following numbers:

• Dump Pressure of a Level 7 Classic Valve @ 300fps before the shot.

• Dump Pressure of a Level 7 Classic Valve @ 300fps after the shot (residual pressure).

• Dump Pressure of a Level 7 X Valve @ 300fps before the shot.

• Dump Pressure of a Level 7 X Valve @ 300fps after the shot (residual pressure).

• Classic Valve dump chamber volume with Level 7 installed.

• X Valve dump chamber volume with Level 7 installed.

Although it is not difficult to obtain these pressure values directly in an experimental setup, I have a doubt there's enough meat in the side of a valve to just start tapping hoses into for measurement. Is there a simpler (safer) way to measure these values other than tapping a pressure sensor into the side? Also, I don't mind sacrificing a classic valve for this - but retrovalves are darn expensive.

there is a sheet of paper that comes with RT valved mags (well might come on classics too, but i got mine used) from the AGD factory... I believe it had something to do with the dump chamber pressure... i seem to recall an 8.5x11 sheet of paper, the top half of which had a line graph of sorts... I'm going to look thru all my old papers on paintball to see if i can find it for you. please correct me if you think the smoke has gone to my brain.

-k