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Unregged 12g CO2 + QEV pop off machine pistol.

Posted: Thu May 10, 2012 2:45 am
by Cosmic Muffin
hey guys. ive been thinking this plan up over a period of weeks. I got inspiration from BTBs' Pnuzi. my idea is similar to his though instead of having it a cloud i would have a 1/8" QEV + relief valve before the vortex chamber, this would keep the fir rate down slightly and create that typical submachine gun sound. An ACA paintball thread 12g CO2 bulb quick change unit contained in the grip will be the source of air. i just want to know if there are any risks in using the 12g bulbs with this sort of setup? and will the bursts of air, rather than constant supply going into the cloud chamber effect feeding? thanks in advance

Posted: Thu May 10, 2012 2:54 am
by jackssmirkingrevenge
This one uses a cloud magazine, seems to work pretty well: http://www.spudfiles.com/forums/anarchy ... 23302.html

what will your feed valve be?

Posted: Thu May 10, 2012 6:37 am
by Brian the brain
My experience with a similar set up is that the bulb will run out VERY quickly.
I tried that on my deathray project.
With plastic bb;s you would get some shots off but with lead bb's it is near impossible.
The short blast is not enough to effectively lift up the bb's.
In the mean while pilot waste piles up fast.

That is the reason I went for a simple straight up gasline into the tiny bb chamber.
Putting as much gas as possible to good use and still it ran out pretty fast.
Between 2 and 3 seconds tops.
Any misfeed or pilot waste ruins the whole thing.

I can only advise you to use airsoft bb's and a small bb reservoir.
That would make a fun project.
Stay away from the QEV/ pop-off combo in this case.

Posted: Thu May 10, 2012 6:54 am
by Cosmic Muffin
cheers for the pointers guys.
feed valve jack? not quite sure what you mean here :?

Posted: Thu May 10, 2012 7:12 am
by jackssmirkingrevenge
Cosmic Muffin wrote:feed valve jack? not quite sure what you mean here :?
What's the valve between the CO<sub>2</sub> chamber and your QEV/pop-off serup?

Posted: Sun May 13, 2012 11:19 am
by Cosmic Muffin
ah of course. Not sure yet, still not really sure what to use. The Pnuzi was made with a pressure washer handle if I'm not mistaken. I was hoping to find a valve that screws directly on to the co2 setup. That way it's less likely to explode and blow my hand apart, as I fear epoxy would. What would you suggest?

Posted: Sun May 13, 2012 12:16 pm
by warhead052
Does it have to be unregged? If not, I would recommend a pistol grip blowgun, with a kobalt air tool co2 regulator, that way you can adjust from 0-120 psi.

Posted: Wed May 16, 2012 3:10 am
by Cosmic Muffin
I was looking at getting the kobalt air reg yeh, but I'm financially challenged at the moment unfortunately :P id prefer if it was unregged and just running off the 12g simply for size.

Posted: Wed May 16, 2012 8:05 am
by wyz2285
but I'm financially challenged at the moment unfortunately
Then what made you decide on using 12g co2 unregulated? It will get expensive in no time.

Posted: Thu May 17, 2012 4:50 am
by Cosmic Muffin
because then its totally portable. i know it will cost a bit, but this thing is going to be awesome. do you think this will be ok? the length is around 25cm. im just going to mod the qev body to have the air inlet higher up. so i can retain the compactness, and ill have it closer to the inside walls of the valve body so it will create more of a vortex effect. do you think ill have any risk with it exploding on me? im submerging the whole thing in epoxy in aid of safety. the "chamber" port of the qev will be plugged and to be filled the bbs are poured through the pilot side. <a href="http://tinypic.com?ref=4gp7ba" target="_blank"><img src="http://i48.tinypic.com/4gp7ba.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

Posted: Thu May 17, 2012 7:31 am
by wyz2285
Probably will work, not efficient through. If I were you I'd go for a semi air-tight detente, save more co2 and I'm pretty sure it will perform better. But it's up to you.

Posted: Thu May 17, 2012 9:00 am
by Cosmic Muffin
Yes a detent of some sort would have been in the equation. I was thinking of using an o-ring so it would create a seal, therefore saving co2 and improving efficiency. Is there anything else you think may make it less efficient?

Posted: Thu May 17, 2012 9:44 am
by wyz2285
Burst is't really good for a vortex system, a continue gas flow would be better. So you vortex chamber should be as small as possible because for a decent power you need to fill it up to a constant high pressure. But too small may create jams. But I'm not sure about the exact size, you may build it to find out, I'm not optimistic about this project through.

Posted: Thu May 17, 2012 10:22 am
by warhead052
Why not make it so the Co2 is like a stick magazine, and its in the shape of a Mac 10? To me it makes more sense aesthetically speaking. Your gun though, so you decide.

Image

Up to you, but it looks pretty bad ass.

Posted: Sun May 20, 2012 4:03 am
by Cosmic Muffin
i think the final product will look more like an mp5 or a tek 9 :)