Will this work?

[Jack_Hogg]

It will be made out of a solid peice of 30×60×150mm Aluminium
Tell me what you think

[jackssmirkingrevenge]

It will be made out of a solid peice of 30×60×150mm Aluminium

Looks like a sound design, I imagine the tolerances will be tight so no reason why it shouldn't work very well.

[Jack_Hogg]

Ok, are there any things you would have changed? Like the size of the holes, or the end plug or something? I want it to be compact as pissible. A bulpup design.

[jackssmirkingrevenge]

I want it to be compact as pissible.

Are the breech block dimensions to scale?

[Jack_Hogg]

No. It's just a scetch. I still have no dimensions. Do you have suggestions on some dimensions?

EDIT
Barrel will be 12mm copper tube (10mm id) resevoir will be 1" 300mm pipenipple. Ballvalve will be ½

[jackssmirkingrevenge]

w-a-a-a-a-a-i-t a minute.

As it is the design won't work.

The piston can't de solid, otherwise there will be no place for the chamber pressure to open it once the pilot empties.

[Jack_Hogg]

Hmm I really have a hard time understanding this..

The pressure behind the piston is equal to the chamber pressure. Once the pressure is released behind the piston, the piston will move down am I right?

[jackssmirkingrevenge]

Look at the diagram, once you empty the pilot, what force is going to open the piston?

[Jack_Hogg]

Now I get it! Thanks!

EDIT:
I placed the ¾" tap in the middle of the piece. Will the sides hold 60bar?
It's about 1,5mm on each side


EDIT #2
I made a scetch of the dimentions. What do you think?

[POLAND_SPUD]

hmm this looks interesting... can to us something more about the design, I mean what sort of pressures are we talking about??

also that looks like a buttstock... that's pretty cool but it means that the BV will be very close to your shoulder... I mean much too close

[Jack_Hogg]

hmm this looks interesting... can to us something more about the design, I mean what sort of pressures are we talking about??

also that looks like a buttstock... that's pretty cool but it means that the BV will be very close to your shoulder... I mean much too close

The pressure I want to use is 50 to 60 bars. That's about 700 to 870 PSI.

You are right about the buttstock. I am planning to build a spring assisted ballvalve.

[POLAND_SPUD]

may I suggest building a spool valve design ??

in this way you could pilot the valve using lower pressures

[Crna Legija]

lol running low on paper, i think that you should use a solenoid valve to pilot it to keep a clean look or even a real small QEV like the ones on paint ball guns

[POLAND_SPUD]

ohh yeah or you might as well mount a small QEV instead of the bv and a QDV... though that goes without saying

[Technician1002]

This design can most certanly work. What the drawing does not show properly is the location of the barrel seal and it's diameter. If the seal is on the OD of the piston, then absolutely it won't work unless converted to a manually opened QDV. There will be no force to open the piston once the pilot is vented.

If there is no seal from the chamber forward so air pressure is on part of the face of the piston and the seal is at the end of the barrel, then there will be pressure on the piston face to open it. The big problem is there is not enough space to keep this pressure on the face of the piston so when it cracks and the piston face pressure vanishes out the barrel, it will stop opening. A piston with a step down in size to permit air into the piston face area will work fine.
Edit, edited the drawing to show the change.

Extending the valve seat closer to the air chamber would improve the performance.

Edited again to show the extended valve seat which results in a shorter ligher piston and better flow to the face of the piston when it opens. All good things.