Pneumatic CO2 T-Shirt Cannon

[helluvamatt]

Pneumatic CO2 T-Shirt Cannon

This is what happens when an ACE Hardware Employee / Teenager is bored.

Overall Length: 5' 3"
Fuel: CO2 @ 800 PSI or Compressed Air @ 120 PSI
Actuation: Modified RainBird JTV-100 Sprinkler Diaphragm Valve
Pilot Valve: Tippmann M98


Pressure Tank
Length: 2'
Diameter: 3"
Volume: 226.08 C.I. (3.7 L)
Max Operating Pressure: 130 PSI
PVC Burst Pressure: 160 PSI

Barrel
Length: 2'
Diameter: 3"

The Paintball marker actuates the pilot on the sprinkler valve. It actually works. However, since the M98 is semi-automatic, why can't the whole gun? Well it can, if the gas' pressure was high enough to blow the bolt back. Unfortunately, the gas has to be regulated down so that the PVC doesn't explode. (Around 120 PSI) So far, I have only been able to dry shoot compressed air. Thanks to a Tippmann 98 Custom Pro Bottomline E Bolt Regulator the gun will become portable feed off of regular Paintball CO2 cylinders. Pictures to follow when the gun is complete!

[homedepotpro]

i wish o could work at ACE, can't wait to see some pics

[DYI]

You're just asking to die if you use a PVC air cannon at only 40 psi below its burst pressure. Please, make it out of something a bit tougher than that. Come to think of it, how did you find the burst pressure? Did you just pressurise a piece of pipe until it exploded?

[hi]

i think he said it wrong. i think he maens that it is rated for 160 psi, not it's burst pressure. id like to see some pictures of it though.

[helluvamatt]

The pressure is printed on the pipe. Plus I only operate the gun at 100 PSI; the valve diaphragm is only rated 130 PSI. Any higher and it will leak open. Making a sort-of "safety" feature. However, there is nothing safe about it. The gun IS unsafe. I only use it to test technologies that will go into my common use model. (The one my school uses to please the crowd at football games!) Which, when perfected here in PVC, will be made out of steel. My CO2 cylinders come nowhere near to the burst pressure of those, which I was told was in the neighborhood of 1200 PSI?

[iPaintball]

He's not "asking to die" by using it at that pressure. PVC usually has a 3x saftey margin, meaning that if the pipe was rated to 100 psi, it'll burst at around 300 psi.

Pictures of the gun would be nice. And welcome to SpudFiles!

[DYI]

Ah, but he said that the burst pressure was 160 psi, not the rated pressure. Would you use PVC that was rated for 50 psi at 120?

[iPaintball]

No, I suppose not, but I do belive he mean "pressure rating"

[helluvamatt]

iPaintball is right, SCH 40 is RATED at 160 Pounds. But it still may burst prematurely if it is handled constantly (IE dropped). However, my gun has been strapped to the workbench for two weeks. I do not believe I will die.

View the picture

[homedepotpro]

why did you paint a demo gun. especially it is is made out of dwv fittings.

[helluvamatt]

notice the paint is unfinished. if testing proves SAFE and reliable then i will finish the paint job.

[noname]

That gun is unsafe and could blow up at any time, completely randomly. The reducers on the chamber aren't pressure rated.

[helluvamatt]

Then what do people make Pneumatics out of? SCH 40 PVC? All of those fittings and pipe are schedule 40. This gun has been pressurized to the point that the sprinkler valve failed.

EDIT: Maybe I should mention that the CO2 will be regulated before it is hooked up. 80 Pounds is enough to lob a T-Shirt into the top row, right?

[homedepotpro]

sch 40 is only the wall thickness. they need to sat NSF-pw on them not NSF-DWV

[DYI]

The schedule of the fittings and pipe have nothing to do with their pressure ratings.

The actual rating on that chamber is around 15 psi or so, due to the DWV fittings.