Page 1 of 1

Coaxial Hammer Valve Idea

Posted: Sat Dec 17, 2011 8:38 am
by DerpWithAGun
Hey guys,

I been thinking lately, the cartridge design which I want to use for my next airgun is kind of going to be a pain in the backside so I have been thinking....

Combining the coaxial design with a hammer valve. I was thinking this because well, the cartridges will be a pain in the backside because I have to make so many, but I really want a hammer valve design without cartridges. But If I have a hammer valve I have to have this huge pressure chamber that will hold 3000psi minimum to be able to shoot at high velocities. So I want this to be coaxial because it looks more awesome and will look more like a real firearm.

So I was wondering, has anyone ever attempted this or know of someone who has?

If I undertake this challenge, my minimum specifications are:
Barrel Length: Around 70cm long
Barrel Dia: 6mm
Chamber Dia: 1/2" / 15mm
Minimum Projectile Velocity: 350 fps
Projectile Weight: 30 - 35 grains (roughly 2 - 2.5 grams)
Maximum Pressure in Tank: 3000 psi (3000 psi is actually pushing it a bit. Might not even need that much pressure for 8 shots)
Minimum amount of shots per recharge: 8


The basic Idea I have for this is that the gun will be activated by pilot valve as normal. The piston will shoot backwards for half a second and then be quickly shut forward by a spring or other force back into the sealed position ready to be loaded with another bullet and then fired.

Tell me what you think guys? Yeah or Nay?

Posted: Sat Dec 17, 2011 9:07 am
by lklaussen
Sounds great, but half a second sounds like a little too long to me.

Posted: Sat Dec 17, 2011 9:43 am
by jackssmirkingrevenge

Posted: Sat Dec 17, 2011 9:44 am
by Hawkeye
That's what Brian did with Old Shat. It's not a hammer valve in the sense you think though. The hammer is just activating the pilot and indirectly opening the valve. You don't need anything like 3000 psi for what you're thinking.

Posted: Sat Dec 17, 2011 7:07 pm
by DerpWithAGun
I'm thinking hammer valve as multiple shots before recharge and that's want I want to do but in coaxial style because I hate having huge air chambers showing. All I really want is just a simple hammer valve but the air chamber and the barrel are in coaxial style. I just thought of having the piston in there so that the gun will be stronger but I'll scrap that idea it seems to hard.

So can anyone tell me, hammer valve with a coaxial styled pressure chamber, has it been done? JSR, your link didn't tell me anything all it was is a simple coaxial.

Posted: Sat Dec 17, 2011 7:36 pm
by jackssmirkingrevenge
Image
All metal co-axial design.
Piston to be piloted by a hammer valve.

Posted: Sat Dec 17, 2011 10:25 pm
by DerpWithAGun
jackssmirkingrevenge wrote:Image
All metal co-axial design.
Piston to be piloted by a hammer valve.
Yes, the valve will be piloted by a hammer valve, that's exactly like my cartridge design, it will just dump all of the air out at once, then you must recharge it. I want it to be piloted by a hammer valve and then make the design so the piston will quickly shut when it opens so I can have multiple shots before recharging with air, if that's even possible.

Might even just make a hammer valve, 2000 psi. Simple as that.

Posted: Sat Dec 17, 2011 10:49 pm
by Crna Legija
BTB's old shat is what you want but use a coax not QEV for a main valve.

Posted: Sun Dec 18, 2011 2:18 am
by DerpWithAGun
Alright, where can I find this "Old Shat"?

Posted: Sun Dec 18, 2011 2:56 am
by Crna Legija
DerpWithAGun wrote:Alright, where can I find this "Old Shat"?
With the might power of search!

Posted: Sun Dec 18, 2011 8:53 am
by Brian the brain
Here she is:
Image

Entire buildlog found here:

http://www.spudfiles.com/forums/old-sha ... 17827.html

long read though.