I made my semi auto airsoft/paintball gun, had fun with it, but am seeking some full auto. I have a home made poppoff valve currently popping around 60-70 psi, and need to hook that up to the qev. How is that done?
here is a pic of the gun currently. its a qev with a slide valve, and about 8 inches of 1/2 inch pipe as a chamber.
Posted: Sat Jan 07, 2012 9:39 pm
by ramses
The popoff valve needs to be attached to the same port as the air inlet.
You may need to restrict flow from your air source to get it to actually cycle.
Posted: Sun Jan 08, 2012 1:39 am
by jackssmirkingrevenge
[youtube][/youtube]
This should be pretty clear.
Posted: Sun Jan 08, 2012 9:29 am
by lklaussen
So if the air in is just on the "small chamber side", how does the diaphragm reset to let it fire again?
Posted: Sun Jan 08, 2012 10:07 am
by POLAND_SPUD
thx to a spring you can see in his video
Posted: Sun Jan 08, 2012 11:26 am
by ramses
Oh, I guess you could do that too...
Posted: Sun Jan 08, 2012 12:47 pm
by lklaussen
How does that reset it though? Wouldn't that just open it when the popoff pressure is reached and just dump the whole pressure tank?
Posted: Sun Jan 08, 2012 1:03 pm
by ramses
You must use a secondary air chamber that is refilled by a much larger chamber.
You fill the secondary chamber through a relatively small (~.2 or smaller) opening. This then leaks into the pilot area around the piston. When the pilot area exceeds a certain pressure, the pop-off quickly reduces the pressure, causing the valve to open. This dumps the secondary chamber through a large (.5" or bigger) opening very quickly. The valve then re-seats and the process repeats.
Posted: Sun Jan 08, 2012 1:20 pm
by lklaussen
Ahh that would make a little more sense!
Posted: Sun Jan 08, 2012 1:37 pm
by jackssmirkingrevenge
ramses wrote:You must use a secondary air chamber that is refilled by a much larger chamber.
You fill the secondary chamber through a relatively small (~.2 or smaller) opening.
Pretty much, but note that this point between the firing chamber and the main chamber is the firing valve
Flow from the firing valve determines rate of fire. Fast flow -> Fast rate of fire and vice versa.
Posted: Sun Jan 08, 2012 2:21 pm
by POLAND_SPUD
Flow from the firing valve determines rate of fire. Fast flow -> Fast rate of fire and vice versa.
which means you could use a flow control valve to adjust ROF on the spot
ohh and yes jsr that was pinky and the brain refference
Posted: Sun Jan 08, 2012 2:25 pm
by ramses
Correct.
If you have too much flow, you may have created a fart machine.
