He is using a pilot system Rob, it's essentially a "push button" valve. Incorporating a lever as the trigger "proper" would reduce the required effort, but I still like a poppet valve/striker for the sake of consistency.Qev optimization is important, some thoughts;Keeping diameter ratios between outer diameter and sealing diameter closer will result in an increased drop in pilot pressure before the spool begins to move...reductions in pilot pressure during piloting are about as helpful as reductions in pilot volume.(both will help eliminate/reduce spool bounce due to re-compression of the pilot volume) A check valve of some sort (floating o-rings or U cups are easy with machined spools) pretty much eliminates any bleed back from the chamber to the pilot...not essential, but nice to have.Total spool travel should be a minimum of 1/4 the sealing diameter. Not much gain, nor much penalty at 1/2 the sealing diameter. The room for travel is of course part of the pilot volume...a trade off of sorts.Keeping spool mass down helps a little, but not as much as a fellow would think. An effective bumper for the spool is a requirement to keep things from self destructing...have used 90D buna washers with nylon and steel spools.Regards,Al
Probably work, but if the ball expands the cup too much, you may be dealing with a projectile the diameter you would get if you forced the ball completely into the cup....Bob
I tried a couple of shots with "The Blaster" on nominal 850 psi air. Results are about 569 fpe for the 84 grain projectile. That"s about 60 FPE! Not bad for a 21" barrel!
Quote from: Doug Wall on September 27, 2018, 09:53:22 AMI tried a couple of shots with "The Blaster" on nominal 850 psi air. Results are about 569 fpe for the 84 grain projectile. That"s about 60 FPE! Not bad for a 21" barrel!that's really good , awesome