The Goblin; a QEV paintball gun

[Xenophile]

Hello spudfiles. I have recently created perhaps my greatest pneumatic cannon to date! I call the beast "The Goblin". As far as the specifications go, I run the gun at around 90-120 psi using a Palmer regulated paintball CO2 tank. I'm using a standard QEV and slide valve set up to enable semi-automatic fire. Ammo is stored in an off the shelf 200 round paintball hopper that fits almost perfectly into the 3/4 inch pressure rated PVC I'm using as a barrel. The air chamber is made from 1/2 inch PVC. As far as the cosmetics go, I'm aware it doesn't look like a real firearm, and that is fine by me. I prefer its striking green color and the "safety" it provides. I do not intend to use this gun in any paintball matches, its simply for target shooting in my backyard. I'd love to hear what you guys think and I hope to get "damage" pictures up soon. Thanks!

[1nxtmonster]

Nice good clean build. I recommend 3/4 cpvc for the barrel, I used it in mine and it is so much of a better fit on the paintball than normal pvc:

http://www.spudfiles.com/pneumatic-cann ... 25537.html

Maybe you could mod the qev for chamber filling (I think that's what you would call it) and pull a 180 on the bottom chamber, so that you could mount the tank in a shoulder-stock type position. Then you could trigger it with a blowgun.

[Lazyboy]

Looks good
How many shots do you get per tank?

[jackssmirkingrevenge]

Not bad, is there some sort of bolt involved? Also, how do you stop the balls rolling out before firing?

[Xenophile]

Believe it or not, the pipe I'm using as a barrel has an almost perfect seal with very little blow-by. I think its a threaded pipe for a sprinkler. I have not yet tested it on a full tank of CO2, but I should get around to it soon. Prototyping uses a lot of gas! I'm curious about how to include a blow-gun as a pilot valve. Is there any link or diagram you could include giving more details? Currently there is no bolt, and balls do occasionally roll out before firing, but it's not a big deal. I really appreciate the feedback and I look forward to seeing some of your cannons in the future. Thanks guys!

[1nxtmonster]

Easy Detent system to keep your paint from rolling out of the barrel:

Screen Shot 2014-03-05 at 5.31.23 PM.png (25.82 KiB) Viewed 5938 times

And sorry for late reply, but here's how to use blowgun: