What diameter is an autococker valve?

[trains are bad]

I'm designing an experimental apparatus. This is not a paintball gun but paintball parts might work.

I have a couple questions about autococker valves. Since autocockers aren't blowback, are they totally sealed to the rear? That is, do they have orings or are they just a 'close' fit with the valve stem? I would be actuating the valve with a pneumatic ram, like I believe angels etc. do. But instead of using an actual ram I would like to embed it as shown, you can see that the same bore the valve fits in acts as the cylinder and then I can just have a piece of brass or something flop around in it for the piston. I just don't know if that will work or if it will leak down the 'barrel'.


I'm open to using other forms of valves (angels, etc) it's just that I'm familiar with autocockers from using them.

What diameter are autococker valves (what size bore do they fit in)?

Oh by the way... just remembered how autococker valves are held in, with that weird nut from behind. That would be extremely inconvenient for me. Is there any rear-sealed valves that are held in like spyder valves, with a setscrew?

[DevilMan]

AC valves are also held in with a set screw like a spyder. The nut in the back (IVG) is to hold the spring which puts tension on the valve to determine how much air pressure it takes in front of the valve to open or close the valve and the dose of air that goes into the bolt when the valve is opened.

The valve is basically the same as a spyder valve, the only diff is that it's closed bolt, not open bolt.

I don't know the diameter but I may be able to get it tomorrow as I have a valve in the garage I could measure.

Good luck with the project.

Oh and do a search for threads I started and look at one called Information Overload. or something like that. It's a link to all the different schematics of how PB guns work.

I think you could find it useful.

DM

[trains are bad]

The nut in the back (IVG) is to hold the spring which puts tension on the valve to determine how much air pressure it takes in front of the valve to open or close the valve and the dose of air that goes into the bolt when the valve is opened.

If I'm not mistaken, you describe the velocity-adjuster that adjusts the tension of the striker spring.

The valve itself is held in both by a spyder-style setscrew, and a strange hollow allen-headed screw that you need a special tool to install or remove. This is how I remember it. I'm not sure if the setscrew by itself would suffice; I calculate several hundred pounds of force on the valve in the worst case, depending on diameter.

The valve is basically the same as a spyder valve, the only diff is that it's closed bolt, not open bolt.

How could the valve itself possibly matter if the marker was open or closed bolt.

I've been looking at pictures online, and it doesn't seem like they are truly sealed to the rear. Many don't even have rear orings. This is annoying. I suppose I could machine my own valve.

[211]

Dragun "The One", Diablo Wrath, and Spyder EM1 all use a spyder style valve, the difference being in the poppit
a standard blowback poppit has a flat spot milled on it to allow air to blowback the striker.
on the markers I listed (and a bunch more besides) the poppit is round and seals with the back of the valve so air from the valve only goes to the bolt

[trains are bad]

on the markers I listed (and a bunch more besides) the poppit is round and seals with the back of the valve so air from the valve only goes to the bolt

But is it really statically sealed or only 'adiabatically' sealed? Is there an actual oring there, or is it just a close fit so 'not too much' air leaks around during the few milliseconds the valve is open?

Most importantly, can I pressurize the back of the valve or will it leak down the 'barrel' if I do so? I have a feeling they aren't sealed from behind. Which complicates my design a great deal, possibly even ruins it.

[Nick E]

I don't think any are actually sealed back there. Air just doesn't really go through them because it's harder to flow through there than the big gaping hole in the valve. Maybe you could machine a lip into the valve and have an o-ring sit against the valve stem.

[trains are bad]

Yes. I suppose it would be fairly straghtforeward to modify a valve, especially if you started with one of the ones that already has two body-sealing orings. Then you'd just have to seal to the valve stem somehow. It could be done. I wonder why makers don't design this way; it would be smaller, lighter, less reciprocating mass, and shorter.

[211]

The Dragun poppit isnt sealed, but the valve for the Type R (a Wrath clone) does have a delrin sleeve/oring in the backside, so it possibly could maintain pressure without leaking

[trains are bad]

That's exciting, but I'm having a hard time finding a Type R valve or even pictures online.