SpudFiles

I'm making my list of fittings to build a 4"-port piston valve next week to replace the 2" sprinkler valve on my can-launching cannon. I'm going to try a modification of a coax-hybrid design to get faster piloting. Anybody wanna put money on LEO? Geocentric? Polar? If my valve idea works, I should be able to fire pneumatically, or fire it as a piston hybrid combustion. Think I can turn a can of ravioli inside out?

With heavy projectiles fast piloting doesn't really make that much difference. Large port sizes do, of course, but the bigger point is that as long as the valve is fully open before the projectile has traveled more than (say) 5% of the way down the barrel, the differences in performance are minor at best.

GGDT agrees with you, but I'm still set on the design. Although, I'm dropping the barrel size to 3" so I can stick with firing #2 cans. I'm going to price out steel pipe and fittings tomorrow. If I can get steel at a reasonable price, I'll be firing it as a hybrid, which I think will make it the largest piston hybrid on the site.


I mathed it out on GGDT as a pneumatic and it came back with 712fps at 200psi.