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CO2??

Posted: Thu Jan 28, 2010 4:38 pm
by NMEMJCM
Hello. I have a lot of experience with map gas launchers and want to move onto pneumatics. Im new to the forum, but not the hobby. My question is can a pneumatic cannon be made using a larger c02 canister from a paint ball marker? would it get the sprinkler valve cold? Im sure a cannon has been made with this plan, I just could not find it. Any pointers or links? Im just trying to get away from air compressors and bike pumps. Thanks!!

Posted: Thu Jan 28, 2010 4:49 pm
by McCoytheGreater
The company Kobalt makes a regulator to attach to any CO2 canister for paintball guns. They sell them at lowes, or you could find one of the same type at Harbor Freight. It reduces the high pressures in the tank to a more manageable psi. I think they can go up to a regulated 220 p.s.i.

Re: CO2??

Posted: Thu Jan 28, 2010 4:56 pm
by velocity3x
NMEMJCM wrote: would it get the sprinkler valve cold?
Yes....cold and brittle.

Posted: Thu Jan 28, 2010 6:08 pm
by irisher
If you do use Co2 make sure to add a pop-off.

Re: CO2??

Posted: Thu Jan 28, 2010 6:09 pm
by Hubb
velocity3x wrote:
NMEMJCM wrote: would it get the sprinkler valve cold?
Yes....cold and brittle.
If the pressure is regulated, the regulators do a good job of fixing this problem. Now, if the pressure is not regulated, the sprinkler valve probably wouldn't survive the first shot.

Now, if you want to see what one could look like...
Image
Courtesy of HazMat.

Posted: Thu Jan 28, 2010 6:50 pm
by NMEMJCM
so, you would not need a chamber as you would with a "bike pump" style cannon then, .....right? The reg regulates the co2 and the sprinkler valve alows the regulated co2 to pass through it to the barrel. Any tips on how to construct? (pressure and barrel length... ill be shooting tennis balls, and golf balls) I, like most people here, dont want to blow up.

Posted: Thu Jan 28, 2010 8:29 pm
by skyjive
You will still need a chamber in most cases as the flow from the CO2 bottle through the regulator will not be nearly sufficient to give you a decent shot. If you build up a large volume in a pressure chamber then release it all at once with a fast valve you will get much greater flow and much better results.

Re: CO2??

Posted: Fri Jan 29, 2010 1:17 am
by jackssmirkingrevenge
Hubb wrote:Now, if the pressure is not regulated, the sprinkler valve probably wouldn't survive the first shot.
800-odd psi through a valve rated for 150 will likely mean that the valve is the first shot :D

Re: CO2??

Posted: Fri Jan 29, 2010 1:24 am
by rikukiakuchiki777
jackssmirkingrevenge wrote:800-odd psi through a valve rated for 150 will likely mean that the valve is the first shot :D
And most of your fingers :D

Posted: Sat Jan 30, 2010 12:20 pm
by jhalek90
Do not use co2.

use HPA (High pressure air)

Most paintball stores sell HPA tanks, and are capable of refilling them.
HPA is filled to around 3000psi, opposed to a co2 tank at an average 850 psi.

HPA is no more expensive than co2, and is better than co2 in the fact that is dose not liquefy at all, and is much easier on your gun.

I bought my HPA tank, regulator, all the fittings, ect for $158 usd a few month ago, and i love it.

I currently can regulate my HPA from 1 to 1500 psi. :-)

Posted: Sat Jan 30, 2010 1:28 pm
by D_Hall
jhalek90 wrote:Do not use co2.
use HPA (High pressure air)
As with so many decisions in life, there is no "right" answer. HPA and CO2 each have their advantages and disadvantages.
Most paintball stores sell HPA tanks, and are capable of refilling them.
HPA is filled to around 3000psi, opposed to a co2 tank at an average 850 psi.
And yet, the energy density of CO2 in storage exceeds that for HPA. Also, there are a lot of areas that don't have paintball shops. As such, getting a paintball HPA tank filled may be a non-trivial proposition depending on where somebody lives.
HPA is no more expensive than co2,
Again, that's locationally dependent. Admittedly, it's not something I've tracked closely in recent years, but from back when I played a lot of paintball you could find areas where HPA was actually cheaper and you could find a lot of areas where it was more expensive. A lot seems to hinge on local paintball popularity and the presence of other industries in the area.
and is better than co2 in the fact that is dose not liquefy at all, and is much easier on your gun.
Not relevant for somebody wanting to make a simple spud gun using a sprinkler valve. At any temperature that you're going to want to be outdoors in, there will be ZERO liquification to worry about on the downstream side of your regulator. What's that? The tank could be significantly colder than the ambient temperature if you're using a lot of CO2? That's true... But again, irrelevant with the type of spud gun being discussed.
I currently can regulate my HPA from 1 to 1500 psi. :-)
And 1500 psi is useful with a PVC-based spud gun... how?

Don't get me wrong, if the user has intentions for semi auto designs or high pressure designs or things along those lines, maybe HPA is the better choice. But based on what's been presented, the "advantages" of HPA are irrelevant and the advantages of CO2 start becoming relevant (energy density being #1).

Posted: Mon Feb 01, 2010 10:23 am
by Hubb
Thanks for clearing that up D_Hall. So many people are so quick to jump on the bandwagon for HPA. Yeah, it's good, but not necessary.

Posted: Mon Feb 01, 2010 4:56 pm
by hoss.josh
McCoytheGreater wrote:The company Kobalt makes a regulator to attach to any CO2 canister for paintball guns. They sell them at lowes, or you could find one of the same type at Harbor Freight. It reduces the high pressures in the tank to a more manageable psi. I think they can go up to a regulated 220 p.s.i.
I bought one of these things awhile back and the quality on them is horrible. If you go with this option make sure to get the warranty that goes with it. My first one lasted two 9oz co2 tanks before the regulator stopped working and let over 200 psi into the line.

Posted: Mon Feb 01, 2010 5:06 pm
by jackssmirkingrevenge
hoss.josh wrote:I bought one of these things awhile back and the quality on them is horrible. If you go with this option make sure to get the warranty that goes with it. My first one lasted two 9oz co2 tanks before the regulator stopped working and let over 200 psi into the line.
It seems to be a fairly common complaint with Kobalt units, perhaps not the value for money they appear to be.

Posted: Mon Feb 01, 2010 5:12 pm
by irisher
I have both a Kobalt style regulator and a paintball regulator. I think if your going to spend the money go with a paintball reg.( I can use HPA and Co2 :lol: )