Pneumatics: CO2 or HPA

[innominate]

Hello all,

I'm designing a pneumatic shifter for our racecar, and I'm stuck as to which gas to use for the propellant. I've read about the effects of temperature difference on the output pressure of CO2, and how if you're not careful, liquid CO2 can enter your system and wreak havoc, but I'm wondering if any of you have other insight from your experiences with the stuff.

Also, all paintball suppliers I've contacted don't produce regulators for CO2 that allow output pressures below 300PSI. How have those amongst you gotten around this?

I offer my thanks in advance.

[Travis Garrison]

I can't pass up a chance to post on paintball gear.

Several manufactures make relatively low pressure regulators...palmer's makes a good product:

http://www.palmer-pursuit.com/online-catalog/stabilizer.htm

But what you are really looking for is the low pressure reg off autocockers:

http://www.palmer-pursuit.com/online-catalog/rock.htm

http://www.actionvillage.com/is-bin/INTERSHOP.enfinity/eCS/Store/en/-/USD/BrowseCatalog-Start;sid=wXkgbgafzdMgNkSdWengxgw5yQhENKkwsAw=?Cat egoryName=paintball-gun-parts-and-upgrades-autococker-gun-upgrades-autococker-regulators

Keep in mind that paintball regs are made to fit into specific systems, and you'll end up paying for it...theres a good chance that almost any pneumatics supply store will be able to sell you a suitable regulator for a fraction of the cost...

...also there was another thread discussing weights of HPA vs CO2 earlier...you should do a search for that one...

-Travis

[EgyptianMagician]

Hey dude, ... do a forum search for HPA ... there was a fairly lengthy discussion on advantages / disadvantages of both...

We are using HPA for ours.