Simple Semi-Auto Paintball rifle

[keep_it_real]

I'm pretty happy with it. The hopper kinda sucks so I'll probably figure out something else. I can get about 6 shots before I have to pump it up again.

Any suggestions?

[turbohacker]

very cool, you should mount the external tank on a backpack.
you should also paint it.
i also like how you redirected the wasted air from the valve back into the barrel, does that improve the performance at all?
ever consider co2 tanks?

[VH_man]

Is this the gun that had the failed Zero valve? I like what you did with that. Improvements........ Make the sprinkler valve actuated by a slide valve, you can buy them HERE: http://www.mcmaster.com/. You want the biggest one. after you stick one of these on, regulate that air chamber and youve got yourself a semi-auto gun that can get more than 6 shots. plus, how does that hopper work?

[iknowmy3tables]

nice job dude, its a work of art. I like the external tank, I'm thinking of doing similar thing with bottles. but nice work, however buying a paintball gun is still cheaper
things you can do: you can try adapting a real hopper, use CO2, try using a Y conection hopper or some gravity flow dwv fitting they suck for presure but have the right shape, but if you only got 6 shots just make a tube clip. adding a presure gauge would be handy for finding out how many shot you got

[alextheametuer]

sweet gun dude i like how you did the hopper and takeing the air frame the sprinkler valve good job how far can it shoot

[COD_FILLETS]

Whats the tank's volume? Nice design though.

[jjk92]

i cant tell for sure from the pictures but is butt of the gun being used as a tank and if not you should somehow incorporate it to hold more air

[COD_FILLETS]

Also, how exactly do YOU fire it? I am aware that you pull the trigger and the modded sprinkler valve opens and air flows through, but I'd guess that would give you only one shot. Do you "cock" the gun every shot? By opening the ball valve, close it than pull the trigger/airgun valve?

[Hawkeye]

I''m not so sure the air from triggering the sprinkler valve is re-directed back in. It looks more like the blowgun is just mounted in a way that gives that impression.

[iknowmy3tables]

hmm this doesn’t look truly semi auto, you have to use it as a double action (open-close ball valve, then pull the trigger) to not waste a lot of gas, go with what VH_man said: buy a slide valve then glue a trigger and a spring to it, only I’m thought it works just with QEVs

[COD_FILLETS]

hmm this doesn’t look truly semi auto, you have to use it as a double action (open-close ball valve, then pull the trigger) to not waste a lot of gas

I think that would have a pretty cool sniper action.

I wonder what the paintball's velocity is.

[StealthSpud]

That's pretty sweet...it actually looks like a paintball gun with the hopper and all! Nice work.

[keep_it_real]

VH_man: It is the same gun. I couldn't find slide valves on mcmaster... Am I blind or is there a different name. Like I said the hopper kinda sucks right now. To hold the paintball in place, I cut up and bent a paper clip and glued it into the T joint so the paintballs don't go everywhere. Instead I might melt two tooth brushes and glue them the edge of the of the T joint. This way holds the paintball back and (hopefully) it centers the paintball before entering the barrel. I'm not sure if you can melt tooth brushes but I might as well give it a try.

It is a actually semi auto. I leave the ball valve open just a little bit so the air floods into the temp chamber slowly letting the sprinkler valve reset. It takes about a second to fill the temp chamber.

The main chamber is approx. 106 cubic inches. The temp chamber is about 12 cubic inches.

I would like to use CO2 put I think it would make the pvc to brittle. Are there any ways to get around this? I thought about regulating the CO2 into a metal chamber that somehow heats it up before sending it on to the temp chamber but that sounds kinda dumb.

Oh ya and by the way, the blow gun doesn't go back into the barrel. The blow gun is behind a plug I put inside the 3/4" pvc so the air wouldn't get into the stock.

[frankrede]

Use co2 but mount the bottle upside down. I think thats what someone said.

[keep_it_real]

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.