truckdiagnostics
Platinum Member
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:
Potato Cannon
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CNC Dan
Veteran Member
I made one with a coaxial barrel and tank. It used a "quick exhaust" valve to fire. Could launch things out of sight. Used 2" PVC for the barrel.
Then I made one that could be breach loaded, out of copper pipe with a 1" barrel.
You can feel the copper get warm as you charge it.
Then I made one that could be breach loaded, out of copper pipe with a 1" barrel.
You can feel the copper get warm as you charge it.
Recreational potatoes are OK, but shooting flaming tennis balls will get the Feds after you.
https://www.spudtech.com/content.asp?id=13
Bruce
https://www.spudtech.com/content.asp?id=13
Bruce
oosik
Epic Contributor
Somebody shoot a flaming tennis ball over here in Ea WA and there will be homeowners looking for them. This time of year its so dry the grasshoppers rubbing their hind legs together can start a wildfire.
I saw a video clip of a PVC/hairspray potato cannon explode - the guy got shrapnel in his arms & chest.
I saw a video clip of a PVC/hairspray potato cannon explode - the guy got shrapnel in his arms & chest.
OP
truckdiagnostics
Platinum Member
The PVC is rated for 250 psi, don't remember what fittings are actually, I did however make sure everything was with in specs including the glue/cement! Gluing it up can be tricky and it takes two people, it is designed so that the air rushes into the center.
Mysfyt
Platinum Member
Can't powder coat that. Bummer!:laughing:
PVC is rated at 0 psi of compressed air.
tcartwri is correct. It may not fail, but it defiantly can.
I was once injured by a PVC compressed air line that failed.
I would suggest you keep onlookers clear of it.
Gary Fowler
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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.
CNC Dan
Veteran Member
And it won't show up on an X-ray either.
CNC Dan
Veteran Member
jwmorris
Veteran Member
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I like potatoes too much to waste them.
I did built a bowling ball cannon though.
I did built a bowling ball cannon though.
Sprinklerman
Platinum Member
A great quick action valve is a 1 inch irrigation valve , you can operate it on a 9 volt battery .
CNC Dan
Veteran Member
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
Veteran Member
I thought those were regular diaphram valves, not quick exhaust valves.
https://en.wikipedia.org/wiki/Piston_valve#Pneumatic_cannon
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.
OP
truckdiagnostics
Platinum Member
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
Veteran Member
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
Elite Member
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.
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.
