A regulator for CO2? no, for my air compressor, as the 120PSI output just hold the diaphragm in the QEV shut and dumps the air out the blowgun when open, or the pop-off valve. So with the ball valve opened a tiny bit, it takes a bit longer for the air to get back into the cannon, thus making it cyc...

thespeedycicada wrote:

The valve would be a Quick Exhaust Valve (AKA: QEV) and would be piloted by a ball valve (manually),

why not a blowgun?

Oh crap! yeah, I meant a blow-valve, but typed ball valve, as that is what I use as a ghetto regulator on my semi-auto BBMG.

You mentioned semi-auto? It is possible to have fairly efficient gravity fed semi-auto that would be pretty air efficient. The valve would be a Quick Exhaust Valve (AKA: QEV) and would be piloted by a blowgun (manually), or by a safety release valve (automatically). if you like, I could draw you up ...

A high pressure sniper works very well. use a small chamber (3 cubic inces or less) and about 400 PSI.

It takes me about a minuite to get to 400PSI on my BB sniper. It has about 2" of 15mm pipe for the chamber. For larger volumes, expect alot more pumping.

I have had one compression fitting fail on me, as in, rip the Olive of from around the pipe. This was because the fitting wasn't tightened fully, and because i was using 400PSI.

Soldered/sweated fittings are much more robust in my experience.

If you are worried about harming the environment, then stay away from combustions. The gases are harmful, but still won't make a difference to the diminishing Ozone etc. Go with a pnuematic and stay away from CO2, as again, that's a greenhouse gas. Use a bike pump or an air compressor and fire away....

I'm not sure if this helps you at all, but here are some plans I drew up for another member on here. You can of course change the barrel diameter etc. to suit your needs.

FEs have been used for BBMGs before and they make quite good ones too. I'm not sure that the grease fire ones would work as they could clog the BBMG itself. The airflow however is small through the FE handle/body so no great velocities will be reached without heavy modification. The refillable CO2 F...

QEV's are fina at 400 PSI. They have no real "failing-point" or weak spot where it would blow up. I have, and will continue to use QEVs at 400PSI.

At first I was half expecting an epoxy cannon, but this is even better!

From the pictures it looks like a 1/2" or even a BB gun, but 2.5" dia. barrel? Wow!

What pressures are you using in this? 120PSI from a standard compressor or like Nitrogen/Helium?

I got 6 12mm (don't know that that is in inches, cba to find out) in one lot from eBay about 2 years ago for around $20. One had a broken diaphragm, so I essentially have 5 working ones, I still have yet to use my other 4 in guns.

You can use QEVs at 400 PSI w/o trouble. I have taken many QEVs up to, and past the 400PSI mark and they work great. The ones I have been using ar Detrol QEVs. 12mm in/out/exh portings. As mentioned, for a 1/4" barrel, a 1/2" would be best, as it allows maximin flow through, and out of the QEV. It m...

A QEV can handle 400PSI. I have 6 Detrol QEVs and they are fine at that pressure. They are ideal for high pressure valves as they open insanely fast. A schrader CAN take 400PSI easily, and will work very well as a pilot valve, but as JSR said, you need your pilot volume to be minimal. Ball valves ca...

A pair of calipers is a great investment for any spudder. Digital ones are even better if you can get a pair.

QEVs that are rated to 150PSI will be fine at 200PSI. It would yeild better performance over a 1/2" ball valve.