Simple Semi-Auto Paintball rifle

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
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Dan003400
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Sat Feb 24, 2007 12:59 am

i have a question what is the point of having that 3/4" or 1" porting sprinkler valve is the hose that goes from the chamber to the valve only has like 1/4" porting if that? Am i rite on this thinking?
keep_it_real
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Sat Feb 24, 2007 11:09 am

Is there such thing as a 1/2" sprinkler valve? Anyway, once all the air does get out of the top of the diaphragm, it will have high flow. So the opening time is just a little slower that's all.
iknowmy3tables
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Mon Feb 26, 2007 2:31 pm

I don't get what your saying Dan, he used the sprinkler valve cause its opens fast and was avalible to him, and the hose is for refilling the chamber so its ok if its small, I think thats what your asking,

by the way since you're going to use a slide valve, you can remove the spring in the valve to get higher flow
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Pyromattiac
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Sun Apr 08, 2007 8:14 pm

awesome man do you specifically what kind of connector i would need to have a co2 tank hooked up to a piece of pvc pipe?
locksmith
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Sun Apr 08, 2007 8:18 pm

nice job looks like a lot of fun.keep up the graet work
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Pyromattiac
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Wed Apr 11, 2007 4:56 pm

hey could you give me the plans for this i'm gonna make a paintball gun for a school project. if you could help me out that'd b great.

thanks
keep_it_real
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Wed Apr 11, 2007 5:59 pm

Just buy a sprinkler valve and get the fittings you want. Read the whole article, especially the part about slide valves and use that instead of my blow gun. Go to palmer-pursuit.com and get a fatty stabilizer to hook it up to co2. the temp chamber is around 10 cubic inches and it fires about 300 fps (same as most pb guns) at 70 psi. If your going to build it so it looks like mine, try and get the sprinkler valve closer to the barrel so there's less dead space.

The hopper in this picture doesn't work at all. You have to make a blow-forward bolt or something like that which is tricky. If you want to keep it easy make a breech loader so you have to caulk it in between shots.
miskaman
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Thu Nov 08, 2007 12:21 pm

keep_it_real wrote:wouldn't that make it more likely for liquid co2 to enter the chamber. And that doesn't really solve the problem of being too cold. Or am I missing something???

I'm a little scared of co2 because it's a heck of a lot of pressure. If one regulator screws up, the pvc is done for.
Yes, having the tank upside down would make the compressed Co2 (liquid) enter the hose or chamber, therefor causing ice to form there and block flow.

Co2 isn't really that cold that it would break the PVC. Fire a real paintball gun once (without paintballs) and put your hand in front of the barrel. It's really not that cold.

Sorry if I brought up an old topic, but I had to offer some advice.
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williamfeldmann
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Thu Nov 08, 2007 2:04 pm

You kicked up a old thread, but since you gave faulty information, I must correct you.
Co2 isn't really that cold that it would break the PVC.
CO2 liquid, which is what would drain out of a non-anti-siphon tank is INCREDIBLY cold. If you want to find out how cold, get a hold of one of those computer dusting cans, flip it upside down and spray your arm. That spot on your arm that hurts like the dickens is now DEAD FLESH. Yes, that fast. The liquid CO2 would be EXTREMELY HAZARDOUS in any kind of rapid fire pvc weapon. The gas itself is not that cold because it warms quickly.

PVC becomes brittle as it gets cold and will explode violently. To see how fast PVC loses its strength check this out. PVC cold temp Failure
If the CO2 is making ice, you can bet its cold.

There have been several people on here that have used CO2 systems on their rapid fire guns, and most of them have complained about the coldness. Some have built metal chambers which voids the cold totally, others have fired more slowly, lots of options.

EDIT: deleted double posty goodness
Trying to figure out how to make a SCUBA first stage regulator work for portable charging station. If only that pesky job thing didn't keep eating up all my time...

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