Sprinkler vs. QEV

[skyjive]

Thanks for all the responses guys, I appreciate the help. I guess I'll either try a QEV pilot or a modded blowgun.

[potatoflinger]

Thanks for all the responses guys, I appreciate the help. I think I'm gonna try using a 1/4" QEV/blowgun as a pilot for the 3/4" QEV and see if that works (which it should, if results are proportional to cost and effort)

They are, this cannon that I made uses a blowgun to pilot a 3/4" QEV, and it has wonderful performance.

[grumpy]

You can't fill from the chamber with a qev.

actualy you can and it is very easy to, all you do is take the diaghram or piston out of the qev and make a very small hole to pilot side. somewhere around here is a thread about it.

[potatoflinger]

You can't fill from the chamber with a qev.

actualy you can and it is very easy to, all you do is take the diaghram or piston out of the qev and make a very small hole to pilot side. somewhere around here is a thread about it.

But that would also decrease performance a little bit by slowing down the opening time.

[skyjive]

Alright, so my trouble apparently stemmed from a classic noob error, I forgot to unscrew the nozzle on the blowgun that reduces flow diameter to a pinhole. This combined with a redesign of the pilot/fill setup to reduce pilot volume resulted in success, finally. I did a controlled experiment using two identical guns, one with a sprinkler valve and one with a 3/4" QEV with blowgun pilot. The QEV shot roughly twice as far at 70 psi.