Adding a popoff valve to a quick exhaust valve

[lklaussen]

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.

[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.

[jackssmirkingrevenge]

[youtube][/youtube]

This should be pretty clear.

[lklaussen]

So if the air in is just on the "small chamber side", how does the diaphragm reset to let it fire again?

[POLAND_SPUD]

thx to a spring you can see in his video

[ramses]

Oh, I guess you could do that too...

[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?

[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.

[lklaussen]

Ahh that would make a little more sense!

[jackssmirkingrevenge]

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.

[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

[ramses]

Correct.

If you have too much flow, you may have created a fart machine.