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Sprinkler Valve for Gas-Blowback?

Posted: Thu Sep 18, 2008 12:09 pm
by sv490665
I got a project for someone with some time, figure out if you can use the hole from the bottom of the solenoid port that leads to the exhaust side of the valve to run a line back to some kind of a push rod which pushes a reloading piston of sorts for a fully automatic gas blowback. This link shows exactly what i mean http://science.howstuffworks.com/machine-gun7.htm Provided you would still need a constant air supply of course to recharge the chamber each time, maybe you can get enough back pressure when you fire to reload the next round... Just an idea. Look at the gray line i made in the picture, the blue on the valve is where the hole is from the solenoid port leading to the exhaust. Green arrows indicate flow direction. This is just illustrating the possiblility of using the hole in the valve itself for getting air pressure back towards a gas blowback system- I'm thinking maybe we don't have to just fill it in with epoxy everytime and actually put that hole to some good use- as far as how the rest of the system is built that would be up to the builder. I think it could work but finding a balance between having enough pressure for blowback reloading while not taking too much pressure supply to the barrel would be the challenge really. Maybe having as small of a blowback line as possible in combination with light reloading bolts would help.

Posted: Thu Sep 18, 2008 1:14 pm
by Brian the brain
Nobody has ever tried that, although the idea of using a gasram to reload has echoed around here for a long time.

Just try it and see.

If it works you'll be idolised for a while

if not...
well..


At least you have an answer to share with us..

Posted: Fri Sep 19, 2008 11:02 am
by sv490665
Ya i might just try it out myself then after i'm done with my sniper project, i wouldn't impliment this idea on that cause i want it to be a bolt-action design anyways, but i do have an extra watermaster lying around here, only bummer is i gotta dig out the epoxy that i used to fill in the solenoid hole. I guess i'll try it out sometime and tell you guys the results.

Posted: Fri Sep 19, 2008 1:36 pm
by POLAND_SPUD
I've had an idea to hook up the chamber directly to a single acting air cylinder.

In theory it works like this -> when the gun is charged the cylinder is fully extended and it closes the bolt.
when you fire the gun the spring inside the cylinder casues the cylinder to retract and this opens the bolt and new ammo falls into its place.
As the gun is being charged again (assuming that either: the flow into the chamber is restricted so that the cylinder has enough time to retract or that the flow into the chamber is closed for a fraction of second with the use of a 3way valve for triggering) the cylinder extends and the whole cycle repeats

I've never tried it though... I couldn't find cheap nor high pressure air cylinders so it's still waiting to be constructed

Posted: Fri Sep 19, 2008 1:46 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:I've had an idea to hook up the chamber directly to a single acting air cylinder.

In theory it works like this -> when the gun is charged the cylinder is fully extended and it closes the bolt.
when you fire the gun the spring inside the cylinder casues the cylinder to retract and this opens the bolt and new ammo falls into its place.
As the gun is being charged again the cylinder extends and the whole cycle repeats
Sounds vaguely familiar ;)

Posted: Fri Sep 19, 2008 3:23 pm
by POLAND_SPUD
I had this idea before I've seen al-xg designs... acctually you were the one from whom I found out that there is something similar to my design...

Posted: Sat Sep 20, 2008 12:09 am
by sv490665
That's cool for a piston valve design, i'm just thinking if i can find a way to make it real simple to mod an off-the-shelf valve then it would become popular to do. Think how popular just modding a sprinkler valve with a blowgun got to be when it was discovered, and that was just to shoot single breech or muzzle loaded shots usually... I'm kinda done with cannons that take like more than 30 seconds to reload for each shot. I won't even make anything without a spring-loaded magazine now. By the way in my current project i came up with a very nice little loading system that works for round projectiles but can probably work for oblong projectile shapes too, i'll post it soon, it's fairly simple but nobody has done it before. I think our hobby definitely attracts enough brilliant minds to engineer some more efficient gun system designs. I know this hobby is big, but let's make it freaking HUGE, i say. I'll get to trying this blowback diaphragm valve sometime in the near future, i've gotten myself very curious about this theory. :D

Posted: Sat Sep 20, 2008 7:05 am
by POLAND_SPUD
well I was planing to use a QEV to make this

Posted: Sat Sep 20, 2008 8:52 am
by grumpy
this sounds alot like the epic ice, that uses a trapdoor that slides back and forth to load paintballs.