SpudFiles

Hi there, new to aircannons and spudfiles, I have build a semi auto air cannon firing 8 mm steel balls, I am using a qev, with air chamber 1” x 6”, with solenoid valve to pressure gauge going to filler, using hpa bottle, when I fill the air chamber to 60psi, then firing the gun it only lets out 5psi not the whole 60psi form chamber, does the problem lie with the solenoid, is it not opening for long enough, any help will be greatly appreciated
Thanks

Welcome to the forum!

A diagram of your setup would help you get better advice.

What kind of solenoid valve are you using? Is the flow from the main chamber still going to the pilot area of the QEV when the solenoid valve is actuated?

Or photographs will help

It’s a 1/4” elec solenoid on a 1/2” qev, I thought once my chamber fills up then pull trigger the air chamber should completely empty, I prob have this set up wrong

Is the part circled a flow control valve or regulator, or does it shut off the system?



Is the Solenoid a 3/2 valve? Are you sure it's hooked up correctly?

Hi there, its an on off valve with pressure gauge to check what’s in the chamber, the solenoid is 1/4” in size
Thanks

Hmmm, it looks correct, what stops the air coming back out through the fill connector when it is unplugged ? That solenoid valve probably needs pilot air to operate (min 20psi ish) but 60psi should be enough, when the chamber pressure gets too low the valve will close even though it still has power to the coil. (you can press the red manual button as well to test it)
Maybe that's the problem now I look at it, the QEV operates to dump the chamber but at the same time isolates the valve which cuts off its pilot air needed to stay open (even if you leave it connected, pilot air is needed at the P port), so really it should be stuttering like a full auto Do you have a 3 way manual valve you can try ?

That's how these work

Thanks for replying, I never take connector off filler as it’s hooked up to a paintball bottle i keep in a ruck sack, I have got it working better now, I have put my pressure to 150psi, it dumps lot more air now, but still find the qev close to quick, would a larger solenoid like 1/2” be better ? You have done a good job on them guns btw

Polymath wrote:would a larger solenoid like 1/2” be better ?

The faster you dump the QEV's pilot, the faster the valve will open so... yes!

Perfect, I understand now, thanks for that

I still think it's a pilot air problem as well, if you have to use an indirect solenoid valve rather than mechanical it might be better to use a 4/2 then you can supply the A port from your bottle and keep the pilot pressure high at all times.
That caught me out before with an air pilot valve, I connected the barrel to the A port not realizing there was an internal port that operated the valve, had to plug the internal port and add an external supply, actually some solenoid valves also allow you to do that

Perfect l, thanks for that, will give that ago, can’t seem to see any 4/2 valves where I live, will have a look, thanks for your help

One of these would be perfect, and you don't need any power https://www.ebay.ca/itm/PT-1-4-Thread-R ... 0005.m1851
This is something I made with a homemade QEV, you get a ready made trigger