SpudFiles

This design, the bolt handle is attached to a tube inside the Aluminium and the light gray part is milled out of the aluminium rod and the slot in front of the bolt is where the ammo goes. (i already have the materials)

Wow jsr... Those marble machines were incredible... Thanks for posting that, I really enjoyed it.

Gun Freak wrote:Wow jsr... Those marble machines were incredible... Thanks for posting that, I really enjoyed it.

Reminded me ofthis, brilliant movie.

Goats, If you make the parts separately it really doesn't identify it as a launcher part...

I like this screenshot.

indeed an awesome movie, that screenshot is my desktop background right now

just ordered me 2 of these QEVs and 2 slide valves... gonna use one set as a pilot for a barrel sealing piston valve (inside a 3/4" nipple, fairly small so I'm thinking it'll pilot it fine..

other set will sit around until inspiration strikes.

hope these puppies can handle 800 PSI....

JDP12 wrote:hope these puppies can handle 800 PSI....

My only concern would be the rubber piston/diaphragm/thingy.

already thinkin bout that.. you said you replaced it with a thin delrin washer to try full auto. so i'm thinkin of tryin to make a steel washer/rubber combo to deal with the rubber diaphragm..

what do you think?

No need for steel, HDPE or delrin should be fine. My delrin only piston leaked at 110 psi, it might not at 800 but I would put a rubber sealing face just in case.

perfect.. that should resolve that problem.

one down, alot to go...

Is it good flow in the valve???

Yes - but it depends for what you want it exactly.

Marbles, airsoft BBs etc - perfect.

Golfballs, Tennisballs - not so much.

Okey,i think i shuold use paintballs or BBs

In response to some questions about the sort of power available to this setup, I hooked up a 12 inch 6mm barrel and did some chrony testing at 120 psi. The firing chamber volume is around 3.5 cubic inches, a little wasteful but that's what I had

Using 0.25g airsoft BBs, I got an average velocity of 590 fps, more than enough to punch through a soup tin. With some adapted 1 gram 0.22" pellets I got an average of 355 feet per second, fairly decent.

In short, even at relatively low pressures with a relatively short barrel, this valve setup packs quite a punch. For say a field legal airsoft sniper, if you fit a longer barrel you could get away with much, much less pressure, a regulated main chamber would last a long time.

Conversely, increasing barrel length and/or calibre, and upping the pressure, you have enough power available to do some serious damage. I might do some testing with steel BBs and marbles down the line.

Some photos, my test setup with Combro CB-625 chrony at the end of the barrel, and a mangled soup tin.

Thanks for this jack, i have all the parts i need to make this and a full auto but need to get my fridge compresser working

Please help :V