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potato cannons Answered

hey, just wanted to see everyone's potato cannon designs. please post yours and I will post mine. a great instructional book on how to make these can be found at your local library, called backyard ballistics.


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9 years ago

I don't have photos. When we were kids we had a mischievous scoutmaster. He had a cannon that we shot tennis balls out of (and occasionally lemons). I guess you could call it a potato cannon. We used duct tape and Kern's Nectar cans. Back in the day of actual tin soda cans, the Kern's cans were steel! They had a hole in the top with a sticky pull foil tab you tried to rip off without tearing it. Sometimes the pull part would rip and you would go looking for a key or screw driver to open the hole lol.

We used a "church key" can opener to put those triangle holes in the top and bottom of each can and taped about 7 to 10 cans end to end (one twit made one 23 cans long, but it didn't work any better). Then we cut the entire top off of 4 cans for the top end that held the lemon. You then use a big fat nail to poke a small hole in the side of the very bottom can, right next to the bottom rim, where the lighter fluid goes.

Fill the hole with 5 or 6 squirts of lighter fluid and swing the cannon so the wind goes across the hole to carburete the fuel. after about 60 seconds you are ready to ignite the cannon. put a tennis ball, lemon in the top (or a potato) and point in the general direction of a target of your choice. Check local laws to see if human targets are off limits. I'm sure pets are :p

I'm KIDDING!! Make some targets with a score system painted on them, it's great fun!

Lighter fluid burns slowly and will not blow apart the duct tape. It is a nice safe fun toy. Yes you can be burned, but you have to be a total dufas. Lighter fluid is what you see burning on some nit wit's hand on some youtube videos as it burns at an extremely low temp. My brother did this to mom when he was about 12 years old and gave her a start. I on the other hand would never light myself on fire, even if offered money to be a stunt man in a Hollywood movie. No way!

When attempting this cannon in your back yard, start with 2 squirts and move up one squirt at a time. You will feel the power each experiment.. 2 squirts will probably not do much, but you will hear and feel the power going thru the cannon.

One final note: Most states have adopted a law against "Infernal Machines" It is a 3rd degree Felony, so be sure to read up in your state. That means any container that you put fuel in and cause a chemical reaction. They are prosecuting teenagers for making dry ice & water bang bombs from 2 liter soda bottles. Sadly they are scaring them into plea bargains and the bottles are not a chemical reaction as described in the law, but rather a physical reaction. Just the same, kids are being labeled as Terrorists by small town police and given criminal records for trying to have good old American fun on a summer afternoon. (British, Scottish, German, Australian and all the kids on the planet are included in my comment, I just happen to live in the USA)

Incidentally, the automobile with its internal combustion fits into the law and is described by each component of the law. Ask the judge in your case to answer if he drove his "Infernal Machine" to the courthouse today. You will at least educate your jury :)

There are also laws against certain types of firearms. This thing is actually a mortar or a bazooka, depending on how you hold it. Pointing it at a Commercial vehicle is a Felony even if it is not loaded. Once the tennis ball or potato leaves the chamber it is considered a "missile" and opens you up to another set of laws. They got you coming and going.

In other words, use this new toy of yours out in the middle of nowhere and let no one see you use it. BE RESPONSIBLE. Irresponsible idiots are what got the laws written up in the first place!