Re: pneumatic potato gun i made
 

One precaution I will give you is that we have been building many air cannons over the years and every time we used pvc because of the cost for supplies and every time we got screwed over. Basically you have to treat it like glass because it will crack slowly with the pressure built up inside and will being put down to the point that it can't be used anymore. You may want to consider using something else.

Just remember, the TechnoKats built a cannon this year and we can shoot into the crowd ~70+ ft. away at 50 psi. :D

Re: pneumatic potato gun i made
 

ok, I tried hot gluing a straw to the other end of the valve and i can shoot mini pellets like 50 feet now.

the pellets are about the size of mechanical pencil erasers. I think i will get a smaller tube ~ .5 in. in diameter and launch baby carrots

Re: pneumatic potato gun i made
 

take all your questions to www.spudfiles.com

if they cant help you, no one can

Re: pneumatic potato gun i made
 

Inline sprinkler valve is the answer for quick dumping of the tank. They work magic. We purchased plans from http://www.americanaircannons.com/plans.html for building a t-shirt launcher (yes its called a "launcher", not gun, shooter, or cannon, the school doesn't like that). The main bit of the project is a 3/4" or 1" in-line sprinkler valve, which has a manual control on the back and the solenoid (which is 24V AC) oddly works with 12V DC off of a spike.

Anyway, here is ours, attached to our 2005 rookie bot:

Re: pneumatic potato gun i made
 

It may just react quicker to a higher voltage.

-John

Re: pneumatic potato gun i made
 

For a Pneumatic gun (Which I don't have much experience with), you're going to want larger/more air tanks (plumb them together in a chain or such) and a sprinkler valve to release the pressure quickly.

Now, if you want help with a combustion potato cannon (check the legality first), then feel free to ask me as I've built two, a 3ft and a 7ft cannon.

Re: pneumatic potato gun i made
 

You don't want the tanks in a 'chain' you want them in parallel. This has already been covered earlier in the thread.

-John

Re: pneumatic potato gun i made
 

Ah. Well, as I stated, I don't have experience with pneumatic systems for potato launchers.