SpudFiles

I assure you that you have (probably) never seen this design before (unless you have been hanging out on UKSGC.) I dont claim that I invented it, I only saw it on UKSGC, but I dont remember who thought it up.

The general idea is that a QEV only is open when the pressure in the pilot is less than the pressure in the chamber. With this setup, the pilot pressure only lowers by a small percentage, so the same is true with the chamber.

To fire, you make sure that the ball valve is closed, then pull the trigger.
To reset it for firing, simply open the ball valve to let out the air, and close it again



This could work with a home made piston, but I have my doubts, since they generaly are not as sensitive as manufactured QEVs.

Thats a great idea, since no air at all is wasted to pilot the valve. Also the qev should reseal with a minimum pressure because there is still gas in the chamber nice idea can't wait to see a cannon using it here.

Oh and a barrel sealing valve with o-rings and a small efficient pilot volume will be pretty close to commercial qev's when it comes to opening times.

I do not understand sprinkler valves at all. Do you think that this same idea would work with them?

Lentamentalisk wrote:I do not understand sprinkler valves at all. Do you think that this same idea would work with them?

NO. I have tried and PLENTY of air will leak past before it seals again. Your best bet with a sprinkler is a ball valve cracked open a small amount so that a very small amount of air can leak past, this will allow the diaphragm to reseat, but takes a few seconds to refill each time.

Damn, well ok, I'll just have to make my marble sniper with a QEV from McMasters...

Lentamentalisk wrote:I assure you that you have (probably) never seen this design before (unless you have been hanging out on UKSGC.)

Or unless the guy who posted it on UKSGC also <a href="http://www.spudfiles.com/forums/copperh ... ml">posted it here</a>

I have plans to try this in a piston valve sometime in the future.

I've made a cannon using two valves for multishot, not sure i have any pictures of it though. And it works fine, but the obviously the power will go down with each shot...

I then replaced the two valves by a slide valve just like Hotwired's design.
The last multishot design used the slide valve the other way around, like Clide's Paintball semi and ran it off a 2L steel backpack tank with a regulator.

I think i have some pictures of the last one...

This is all I have:

Yeah i know too much tape, and that cardboard magazine is sad.
I was jsut trying out a copper shell ejecting system.

I also used this same system on a small copper Coaxial.

to Lentamentalisk here is the best diagram i have found to date of how a sprinkler valve works: http://content.answers.com/main/content ... _Valve.png

battlemonkey wrote:to Lentamentalisk here is the best diagram i have found to date of how a sprinkler valve works: http://content.answers.com/main/content ... _Valve.png

Im confused as to how the pilot equalizes with the chamber...

if im not getting this completely wrong, wouldnt it be possible to fill up the chamber from the blowgun?

My bad should have read the post and not just looked at the pic's.
Its a good idea but i would like to know how much performance/distance you use per shot.