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PSVR-2
circa 1999
Every source I could find on the Internet was telling me how much more powerful than a combustion gun a pneumatic gun can be. I have an air compressor, so I figured I'd give it a try. I only paid something like $20 for the CSVR-1 (and most of that was for the sparker). I think I figured I put over $100 into the PSVR-2. (That includes the two valves I ordered online that were never charged to my credit card. I love free stuff.) PSVR-2 was also immensely complex for only my second potato gun and my first pneumatic. However, I managed pretty well, and the only problem I had was a leak between a threaded PVC fitting and a metal nipple. I haven't been able to fix the leak completely, but it's now such a small leak that it's not a problem.
Here it is sitting on the floor of my room. My room contains a high level of entropy. (Click for larger picture.)
This picture should give a better sense of scale.
The thing I'm most proud of on this gun is the breech loading chamber. When I thought up the idea for how to do it, I'd never seen it done anywhere else. Even now, I've only seen it done on one combustion gun. It works, but it has its faults.
At the time I built this monster, the only way I knew of to trigger the valves was to rig up an electrical system. Mounted in the handle in the front is a toggle switch (safety), a momentary pushbutton (trigger), and inside are three 9 volt batteries wired in series to make 27 volts. The valves are designed to run on 24 volts.
This gun is currently out of commission, because I am converting the triggering system from electrical to pneumatic. This will not only simplify it (no need to worry about dead batteries), but it should boost performance.
Specs
barrel diameter: 1.5" [3.8 cm]
barrel length: ~84" (7') [2.13 m]
chamber diameter: 3" [7.6 cm]
chamber length: ~38" [96.5 cm]
C:B ratio: ~2.07:1
special features: two 1" electronically triggered sprinkler valves, special breech loading chamber