SpudFiles

Ive been looking for such a small valve for years in order to make the Aussie holy grail= a semi Auto,unregged co2 pistol but unless a particular valve is rated over 800 psi and able to take co2 then I wont use it.....

i want to open the valve mechanically, so that the valve is just opened momentarily and consistently. any ideas?

@django-
I have tested the valve, and even brought it to extremes. I tipped the co2 tank over and held down the button. liquid co2 got in the valve and the outside was completely covered in a thin layer of "ice" once it froze I let the valve reseal and it worked perfectly.

You could use a solenoid and a momentary switch, or some geared system with a cam, where the cam would actuate the valve itself.

I'm not so great with electronics... maybe an air-ram and a DCV? but that may be kinda bulky and air-wasting. I could try a gear system similar to an airsoft AEG...that gives me potential for selective semi/full/burst firing if I pulled one out of n old airsoft gun

Just create a trigger piece to actuate the valve. That's the most simple solution, and will make it easier to achieve semi and full auto firing depending on your loading setup.

Wouldn't this send your efficiency down the drain.. With a hammer valve it would ONLY be open for a tiny amount of time, which would be the same every shot.. If you had just a trigger setup, it would be based on how fast your finger is, and I can guarantee your not that fast... Each shot you would be using about 3 times the necessary amount of air, which would get expensive when it comes to refilling etc.

Well I still think the cam would be a good idea, assuming you could get one that is relatively near frictionless. Gear that up somehow and you should be good. Each rotation it makes would be one valve actuation. It would be consistent and still fairly simple.

With a hammer valve it would ONLY be open for a tiny amount of time

He is using the push button valve AS the hammer valve. The dilemma is working out a semi auto cycling hammer mechanism to actuate the valve. It is very easy to create a single fire hammer. Not so much if you want true semi/full auto.

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

Maybe you could try something like Brian? This sort of hammer should be pretty simple, just add some latch to hold it down.

"Do you feel lucky punk?"

Lockednloaded wrote:i want to open the valve mechanically, so that the valve is just opened momentarily and consistently. any ideas?

@django-
I have tested the valve, and even brought it to extremes. I tipped the co2 tank over and held down the button. liquid co2 got in the valve and the outside was completely covered in a thin layer of "ice" once it froze I let the valve reseal and it worked perfectly.

Well it does seem that valve can indeed handle the co2 but for how long I wonder? I want to be 100% if im holding a homemade air pistol in my hand with 800 psi ontap that it wont explode .


The Clippard MJV-3( Normally closed) sounds like it may be the same or similar to the valve you have? http://www.clippard.com/store/display_d ... ?sku=MJV-3 but again this too is only rated at 300 psi.

Though I would think at higher pressures would be hard to push,Im running the clippard MJVO-3( normally open)) on my 9mm semi Auto rifle and I cranked up the psi one day ,pretty high and indeed was quite hard to push the button in.

My plan was to try make an air pistol as small in size as I could running =
Unregged co2.
12 gram co2 Bulbs.
1/8" qev with small chamber.
some small pilot valve that can take 800 psi

this for me is the holy grail of airgun making as I love them and allways have mates pestering me to make them an Air Pistol but in all these years of research still not cracked it

My plan was to try make an air pistol as small in size as I could running =
Unregged co2.
12 gram co2 Bulbs.
1/8" qev with small chamber.
some small pilot valve that can take 800 psi

This may be of interest

[youtube][/youtube]

Dunno 100% what's been done there but looks like he's put one of those 16 gram bike tyre inflators in the gun. looks very wastefull on co2 and the one I want to build will fire either .177 or 6mm steel bbs never the less quite an interesting clip

looks very wastefull on co2

Incredibly wasteful.. More so just an idea that could be greatly improved with a some skills.. Best change would be to not have the revolver setup.. eliminate that and it would be a crud load better

It held co2 overnight, I'm pretty sure I've put this valve through all the abuse it would be subjected to in an air gun. I'm currently out of co2 and out of town, but I've run every test I could subject this valve to.

Now that safety concerns are out of the way, what I'm confused about is how the hammer just "taps" the valve momentarily, I could make a hammer mech that would hold open the valve, but a momentary tap is the goal here.I'm thinking a hammer housed in a tube with a weak spring. When fully extended, the spring should not have enough force to open the valve, but with some momentum, it can open the valve for just a moment.Initially, I'll aim for a repeater before I try to tackle semi auto

I think the only way you'll achieve your goals is either to pneumatically actuate the hammer, which would be a big mess requiring a secondary valve, or work some sort of partially toothless gear to pull back the hammer similar to the gear box of an eletric airsoft gun like you mentioned earlier in the thread.

This is all doable, you'll just need to get your elbows dirty.

I'll probably buy a cheap airsoft gearbox and see how it goes if no one has any other ideas

you can use a staple gun as the hammer, a cap gun or the mechanism used in zip guns