Pneumatic powered cannons.

[Ronald_raygun]

I've been considering ;aunching promotional items at various sporting events held at our school. However, I'm not too sure how to go about the pneumatic launcher.

We have a variety of valves possible including the usual ball valve, a diaphragm, and piston valve

And a final design similar to these cannons. (the top has a separate air chamber underneath the barrel, the bottom has the barrel inside the air chamber)




With regard to the diaphragm and piston valves, would the kit solenoids help at all?



For those that don't know how a diaphragm or piston valve work allow me to explain.

Two barrels, one smaller than the other, are coxially aligned. A diaphragm is placed so that then the air behind it is pressurized, the diaphragm is pressed against the inner barrel.

Air leaks around the edge of the diaphragm and into the rest of the pressure chamber (Remember, the air doesn't go out of the barrel because the diaphragm has sealed it. )

Once the pressure chamber has been filled to the desireable PSI, the air behind the diaphragm is vented out. With the unequal air pressure, the air in front of the diaphragm pushes it backwards. Now that the diaphragm is sealing the fill valve of the air chamber, the pressurized air instead goes out of the now open barrel end accelerating the projectile that was placed inside.

The for operation fo a piston valve, simply replace the word diaphragm in the description with piston.