Potato Cannon

[CNC Dan]

PVC explodes into lethally sharp shrapnel.... Just so you know. Btdt.

And it won't show up on an X-ray either.

 

[CNC Dan]

Your design puts a lot of lateral loading on that discharge pipe with every "firing" and will eventually cause it to break at or around the union. PVC is very brittle and gets worse with age and cold so I would be very cautious about using that thing. There is a reason most potato cannons are in-line with everything. Each bend also gets hammered with air hammer effect when discharging. DO yourself a favor and destroy that thing before you get maimed or killed by it.

Good points.

At the very least, wrap it with filament tape.

 

[jwmorris]

I like potatoes too much to waste them.

I did built a bowling ball cannon though.

 

[Sprinklerman]

A great quick action valve is a 1 inch irrigation valve , you can operate it on a 9 volt battery .

 

[CNC Dan]

A great quick action valve is a 1 inch irrigation valve , you can operate it on a 9 volt battery .

If the valve is big enough. You need a valve that is bigger than the barrel size, or you could have a serious restriction.

When you get up to 2" barrel size, valves gets expensive.

I made my own, and it worked great, but a 4" PVC pipe at 100psi (air) is unnerving. I played with it for a while, then took it apart.

Glad I did it, won't do it again (with PVC).

 

[CNC Dan]

A great quick action valve is a 1 inch irrigation valve , you can operate it on a 9 volt battery .

I thought those were regular diaphram valves, not quick exhaust valves.

https://en.wikipedia.org/wiki/Piston_valve#Pneumatic_cannon

 

[Hiltz]

Works really well! swear it will go a mile. When you pump 130 psi into it is kinda scary as you can feel the PVC expand.:cool2:

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You would get a tighter fitting potato (thus longer distance) if you beveled the inside of the pipe rather than the outside of the pipe.

 

[truckdiagnostics]

You would get a tighter fitting potato (thus longer distance) if you beveled the inside of the pipe rather than the outside of the pipe.

The outside edge is beveled so that you can cut the potato when you jam it in. Tight fit has not been the issue. You have to close the valve when you load it other wise peelings get into the valve. You end up with such a tight fit you can't push it in.
I have a shipping blanket with a hole in it that I have been covering it when using. Yes, pvc shatters when it breaks, I do believe I will wrap it in duck tape and use the shipping blanket.

 

[CNC Dan]

The outside edge is beveled so that you can cut the potato when you jam it in. Tight fit has not been the issue. You have to close the valve when you load it other wise peelings get into the valve. You end up with such a tight fit you can't push it in.
I have a shipping blanket with a hole in it that I have been covering it when using. Yes, pvc shatters when it breaks, I do believe I will wrap it in duck tape and use the shipping blanket.

If you put most of the bevel on the outside, and just a little bevel on the inside, you can trim the excess potato, and get a tight fit. A tight fit isn't so necessary with a pneumatic cannon, as with combustion cannon.

And see if you can find the kind of tape that has the little fiberglass strands in it. Much stronger than duck (duct) tape.

 

[Mace Canute]

A long time ago back over 40 years ago the guys at work told me about a potato gun they made at work. They made it out of three inch 6061-T6 schedule 40 aluminum pipe and had the welder tig weld up one end. They used a water soaked roll of paper towel or toilet paper (not sure which) for a projectile and a spray bomb of ether (the real stuff) starting fluid for propellant. For some reason they tested it inside the building which in retrospect wasn't the best decision...go figure, eh. They shot that wad of soaked paper across the shop and it cracked a Cindercrete block in the wall (I did see the block) and actually shook the building enough to get the people in the office part of it out to see WTF was going on.