I was toying with a 1.5" chamber and barreled sprinkler valved gun the other day.
I had lost interest and not finished it, but my parts between two places, I got it finished (felt like spudding).
I had no pump, and no connections for my new fridge compressor.
So I connected a clear hose from a fix-a-flat can with super glue and a small hose clamp to a modified blow nozzle tip. (The cone shaped rubber tipped one, smaller thread section sawn off, rubber tip cut off).
I threaded that into a propane torch base (brass valve part with brass nozzle removed).
I threaded the tire valve part of the hose onto the shrader on my gun chamber and voila, it gave bursts probably rapid enough for semi-auto.
It would be faster if the chamber was one inch or smaller.
It fills faster with the propane inverted because more liquid flows too.
EDIT:It would fill much faster through a hose barb instead of shrader (maybe too fast(?))
The design would be simple to add a blow forward bolt to.
Perhaps the bolt could be constructed from:
two reducer bushings,
a coupling (larger than barrel),
a few large washers (epoxied to bolt),
a spring,
and a "T" for the magazine.
Pretty simple, and no need for much machining.
Oh, a pressure switch (bought or homemade) could be added to the chamber, connected to the solenoid on sprinkler valve for full auto, or an indicator light to show proper pressure between shots.
Good thing when I modded the valve, I left the solenoid intact also.
BTW, noticed it pilots much faster with no hose between the blow-gun.
Guess I'll run a bar from a seperate trigger to the nozzle trigger.
8)
If you're interested in similar, I can try to check sizes tommorrow on components if I get a chance for you. The candies are 1/2" ???
EDIT:
Duh, "Fit 1/2" shedule 80"
Also that propane (added) smell made me a little sick for a day, mostly when i thought about it.
Not sure if they have schedule 80 stuff at my local Home depot...Do schedule 40 fittings fit OD on it ???
