blow forward pop-off valve

[wyz2285]

Ah now I understand it! very nice! I think the ammo won´t move significantly before the valve opens, but why not try it? this looks like a good way for full auto

[MrCrowley]

I'm a little lost, does the design rely on air getting behind the yellow piston thingy to move it forward?

[jackssmirkingrevenge]

I'm a little lost, does the design rely on air getting behind the yellow piston thingy to move it forward?

Pretty much, the "yellow piston thingy" is held by the spring. Air from the blowgun leaks into the pilot area and starts to overcome the spring strength, pushing it forward until it eventually leaks and pilots the main piston.

Again, it leaks more than pops but as long as LeMaudit is happy with the TAKTAKTAKTAK, hey...

[LeMaudit]

It does POP quite a bit in fact
If I'm not mistaken looking at the 1000fps video, the valve vent its pilot volume in 2 milliseconds and fully open in 2 more milliseconds. That's 4 to 5 milliseconds to goes from fully closed to fully open. How does that compare to other valves? Numbers anyone?

[MrCrowley]

I believe typical piston valves are between 5-10 milliseconds and spring loaded ball valves about 25ms. Just off the top of my head, can't be certain on those figures.

[jackssmirkingrevenge]

It does POP quite a bit in fact

My explanation is that spring + weight gives the bolt a fair bit of intertia, so when it finally gets going, it's really going