What if we where to mount a very small poppet valve behind the chambered ball that would be activated when the hammer hits it then let the air out through the front firing the ball down the barrel? might need to work in a larger area though or you would never get it upto velocity... hrmm....
Both the DRV (pictured on the previous page) and the Crosmann 3357 revolver used essentially a small poppet valve that's pretty similar to a Nelson pump valve turned inside out. The Goblin shell valve is also in some ways similar though more complex as it is filled from the same valve that lets out the air. In all, it's simple, and it works. Velocity seems to be an issue with the 3357, and consistency and long-term maintenance are things I have no clue about with such a design. But it seems that those things are more-or-less going to depend on quality of materials and the limitations of the 12-gram. The engineering challenge is simply designing the valve to give you enough juice for your ball, and packaging the traditional revolver trigger mechanism in such a way that is easy to manufacture and maintain.
Then the real hard part, the design challenge, is making it look like an appealing revolver that someone could put up next to a Colt or a Ruger or a Smith and Wesson and say "this belongs" vs the current models; where the Crosmann feels like a toy, and the DRV is essentially an engineering concept model. Art is needed.
Last edited by HipboyScott; 08-16-2013 at 01:33 AM.
could not agree more with the art thing, I'm not usually a milsim type guy at all but I love pistols and I think it would as you say "look like it belongs" plus it would be fun as hell to play with I kind of want to bust out my old fluid power txt book and crunch some numbers on this to see how small we could make the valve. Now correct me if I am wrong here but does barrel length not also play a role in velocity? if "F=PA" and you have a good underbore with no porting your "A" would increase as the ball travels down the barrel and with a constant "P" your force would go up correct? Or for that calculation would you treat the surface of your ball as a constant "A" and pressure would be the one that would change?
So in theory (not sure about efficiency) if we had our springs weighted correctedly holding the valve open for just the right amount of time and we had the proper length of control bore with a good underbore sealing it all in our space behind the ball would essentially become the dump chamber allowing us to use a super tiny valve as long as it can keep up with the flow?
wow kinda ranted there... Please let me know if I am way out to lunch on this guys
I'm more artist than engineer (in fact I'm about the opposite of an engineer when it comes to math and formulas) So I'm not much for paintball valve dynamics, tho I have had my share of ideas for valve layouts in the past. In general, you don't need a whole lot of volume behind the ball for a dump chamber on a single-shot valve using high pressure air: but you I don't think you can get away with just using direct porting up from your reservoir without having some massive diameters.
Anyway, I'm sure barrel, the cylinder seal, and other factors would all come into play. I've always wanted to do a nice revolver, someday I may.