Potato Cannon

[brianh]

After just making inventory in the shop for the past 6 months I had a small break to just do whatever so why not a potato cannon.

It is all scrap I had besides the solenoid sprinkler valve. I cut the elevation gears out of red oak on the cnc. Using this program I bought it years ago it will export dxf for machining. The free online version you can print from. https://woodgears.ca/gear_cutting/template.html

I am going to make a steel containment box around the valve in case it blows. Test fired a potato way more velocity than the usual hairspray fueled ones.

 

[tncatadjuster]

I got more distnce out of AXE body spray, way better than final net.
Your set up looks great.

 

[larry4406]

Go big or go home!

Need a video! Here, hold my beer!

 

[Ohmthis]

That is too awesome! Brings back memories of the one my brother and I built. We used ether and it was amazing!…….Until the cap blew off the end! It was way too powerful for our set up, but was such a fire show!!!

 

[brianh]

That is too awesome! Brings back memories of the one my brother and I built. We used ether and it was amazing!…….Until the cap blew off the end! It was way too powerful for our set up, but was such a fire show!!!

I charged the tank to 120 psi, quite a bit of recoil movement and it is louder than I expected.

 

[kaymccampbell]

That is really nice. I like the propane tank. You can also remote it with a little hose and a blow gun, instead of the battery pack. That way you don't have to hunt down good batteries everything you want to use it. Somewhere online is the instructions for modding the sprinkler valve. I think this is the resource I used.

Air Cannon Remote Control Sprinkle Valve Modification "Build it Yourself"

Modifying a Watermaster Sprinkler Valve to be used as a Remote Air Cannon Trigger System

aircannonplans.com

 

[HalfTonTom]

Some day in the far distant future someone will start a "WTF is this thing?" thread with a picture of this potato cannon.

 

[gregs]

Back in the olden days, you know the late 70’s early 80’s we made tennis ball cannons. They were made from old style soda cans that had crimped on tops and bottoms. You used a can opener to remove the top and bottom and electrical tape to join them together for the barrel. The last can on the bottom had its bottom cap still on with a small hole punched in the side. We used lighter fluid. You squirted some down the barrel and waved it back and forth to vaporize it and stuck a tennis ball in the end. Little squirt in the hole at the bottom and lit it with your lighter, kaboom. Basically everything was free except the lighter fluid you bought at the drug store. It was very effective and launched the ball pretty far, extra points if it blew apart in your hands! One time for “fun” we stuck it in a plastic newspaper mailbox and it shredded it. Ah good times.

 

[Rickster]

The wife found a potato on the lawn. No bite marks like a animal dropped it. Just a lone potato in the middle of the yard. Her and neighbors thought I was nuts when I said "Potato gun"....

 

[jblnut]

I built an air pressure canon years ago using a 60 gallon air tank, a 2 inch ball valve, and some stainless steel milk line piping from our old dairy barn. With a 20 ft barrel it would shoot a golf ball over a half mile !!

That one you built looks a tad more refined than what we had and I as well would love to see some videos of it in action !!

 

[Bad Habit]

Somebody on the local Craigslist a while back had a bowling ball cannon up for sale. Wife would not let me get it

This though, she wouldn't now about till it's too late

 

[larry4406]

Back in the olden days, you know the late 70’s early 80’s we made tennis ball cannons. They were made from old style soda cans that had crimped on tops and bottoms. You used a can opener to remove the top and bottom and electrical tape to join them together for the barrel. The last can on the bottom had its bottom cap still on with a small hole punched in the side. We used lighter fluid. You squirted some down the barrel and waved it back and forth to vaporize it and stuck a tennis ball in the end. Little squirt in the hole at the bottom and lit it with your lighter, kaboom. Basically everything was free except the lighter fluid you bought at the drug store. It was very effective and launched the ball pretty far, extra points if it blew apart in your hands! One time for “fun” we stuck it in a plastic newspaper mailbox and it shredded it. Ah good times.

Hah!

We called them Polish Cannons back then, not PC now.

We alternated Pepsi product and Coke product cans back then (1970-75). Forgot which, but one of them had a necked down crimped on lid & bottom which would interference fit perfectly with the other. Nesting them made the net tube nice and straight and tight. Duct tape and all was good. These were steel cans back then and not today's aluminum.

We did not try the mail box thing.

 

[signcrafter]

Nice. I built one from some 2" galvanized pipe, quarter turn ball valve, and a Schrader valve to charge it. Looks like a bazooka and worked pretty good. I've charged it up to about 150 psi and it will launch things pretty good. My air chamber is pretty small compared to a propane tank, just a 2 foot length of 2" pipe. Always wanted to increase that but never got around to it.

 

[ZRX61]

If you build a .75 Cal version you can fire frozen tater tots.

I have one that fires 1.5in taters. Tested it from my garage across the road into the desert & fired it just as a cop drove past...
Oops.
Screeched to a halt, backed up, walked up my driveway. Started out as a fairly pointed, one sided conversation. He ended up leaving with a smile & the materials list...

 

[bmw57isetta]

If you like potato guns, you'll love the Punkin' Chunkin' World Championships. What they show on TV doesn't begin to do justice to the unlimited guns. Current official world record is 4,695 feet although there was a guy in Utah that shot one over 5,500 feet. Don't know if it's still a going thing due to Covid and an accident a few years ago but worth checking out. Used to be aired on the Discovery Channel after Halloween.

 

[scooterbum46]

From the mid 70's:
Chevy C10 driveshaft with one end cut off just behind the u-joint, a Champion spark plug brazed in a hole at the base, a piece of 3/8 steel tubing about a foot long brazed in another hole close to the plug. A chrome ACCEL coil hung on the barrel with a hose clamp. Rubber tubing to fit he steel tube and your choice of fuel (propane, or, my choice - my oxy/acetylene torch). A tennis ball or a beer can would fit perfectly if you wanted to do more than make a bang. Propane was our entry level into this, then acetylene, then a good OA mix. We launched stuff we never could find . The OA torch had a pilot on it for production use, we forgot to shut it off one day, went in the house for lunch, picked up the ignition switch when we returned and clicked it (nervous habit, still do it with the lock key on my key fob) and got a muzzle flash like a 155 mm. My dad was still living next door, looked out the window and gave me "that look" ..... the neighbor and I decided we'd probably better put it away.

That was better than 40 years ago, yup, still got the cannon, but aluminum beer and pop cans are a few thousandths bigger now, won't drop down. Tennis balls will

 

[brianh]

If you like potato guns, you'll love the Punkin' Chunkin' World Championships. What they show on TV doesn't begin to do justice to the unlimited guns. Current official world record is 4,695 feet although there was a guy in Utah that shot one over 5,500 feet. Don't know if it's still a going thing due to Covid and an accident a few years ago but worth checking out. Used to be aired on the Discovery Channel after Halloween.

There used to be one like this by me behind a farm greenhouse, it was huge but not nearly as pretty, it was more mad max rust.

 

[Adaylate]

Back in the day my BIL was building a potato gun out of pvc. He went into the plumbing store, he found everything he needed except the cap. The clerk asked if they could help. BIL said I can't find the pvc caps and the clerk says I'll be right back, we have to keep those in the store room because all the kids are building potato guns!

 

[ZRX61]

I accidentally hit my neighbors metal shed one day, made a really loud CLANG!!!. His son (in his 40's) stuck his head over the wall & started berating me... at which the old guy appeared & said "let me show ya mine!".. & came back with one he'd built in the 1950's from cast iron black pipe. Son just shook his head & walked away.

 

[oldmachinenut]

From the mid 70's:
Chevy C10 driveshaft with one end cut off just behind the u-joint, a Champion spark plug brazed in a hole at the base, a piece of 3/8 steel tubing about a foot long brazed in another hole close to the plug. A chrome ACCEL coil hung on the barrel with a hose clamp. Rubber tubing to fit he steel tube and your choice of fuel (propane, or, my choice - my oxy/acetylene torch). A tennis ball or a beer can would fit perfectly if you wanted to do more than make a bang. Propane was our entry level into this, then acetylene, then a good OA mix. We launched stuff we never could find . The OA torch had a pilot on it for production use, we forgot to shut it off one day, went in the house for lunch, picked up the ignition switch when we returned and clicked it (nervous habit, still do it with the lock key on my key fob) and got a muzzle flash like a 155 mm. My dad was still living next door, looked out the window and gave me "that look" ..... the neighbor and I decided we'd probably better put it away.

That was better than 40 years ago, yup, still got the cannon, but aluminum beer and pop cans are a few thousandths bigger now, won't drop down. Tennis balls will

I made one out of an old Chevy truck driveshaft too. Mine fit through the center hole of a old wheel with the tire still on for weight. It was slightly angled like a mortar. My brother and I did transmission rebuilds and engine work in Mom and Dad’s garage so there was an abundance of empty Brakleen and 2+2 cans that fit the I’d of the driveshaft perfectly.
We drilled a 1/4” hole several inches from the end for ignition with a lighter. We fueled it with a couple chunks of calcium carbide and a shot of water, then rammed a “wad” of newspaper To just above the touch hole. It would send the cans a block or 2 away. When we ran out of cans we switched to “canister rounds” (green apples). There was a barn with a metal roof over 2 blocks away and at night you could hear the apples pummeling the roof.

 

[Ran when parked]

Outstanding design by the OP. Black walnuts with the husk still intact work pretty well. They're best after they have been laying on the ground for a few days and the husk has softened a bit. Use a broom handle as a ram rod. You learn quickly which walnuts are soft but not too soft.

 

[arrowhead]

I built one to throw the large 4" tennis balls for my daughters dog. Worked pretty good except she wouldn't bring it back so I just had to go get her and the ball anyway.

New video · Saturday, Apr 18, 2020 🎬

Tap to view!

photos.app.goo.gl

 

[Bigblue&Goldie]

I was at my wife's cousin's farm in Colorado and they pulled out an old potato gun at a family party. Her uncle had a medical oxygen tank in his shop that he would breathe off of every now and then while drinking (don't ask me why, he didn't need it ). He grabbed the potato gun, a propane torch, and that oxygen tank......holy hell did oxygenating the combustion chamber make a huge difference!

 

[no704]

From the mid 70's:
Chevy C10 driveshaft with one end cut off just behind the u-joint, a Champion spark plug brazed in a hole at the base, a piece of 3/8 steel tubing about a foot long brazed in another hole close to the plug. A chrome ACCEL coil hung on the barrel with a hose clamp. Rubber tubing to fit he steel tube and your choice of fuel (propane, or, my choice - my oxy/acetylene torch). A tennis ball or a beer can would fit perfectly if you wanted to do more than make a bang. Propane was our entry level into this, then acetylene, then a good OA mix. We launched stuff we never could find . The OA torch had a pilot on it for production use, we forgot to shut it off one day, went in the house for lunch, picked up the ignition switch when we returned and clicked it (nervous habit, still do it with the lock key on my key fob) and got a muzzle flash like a 155 mm. My dad was still living next door, looked out the window and gave me "that look" ..... the neighbor and I decided we'd probably better put it away.

That was better than 40 years ago, yup, still got the cannon, but aluminum beer and pop cans are a few thousandths bigger now, won't drop down. Tennis balls will

Use a coors light can, they are smaller.

 

[oldtractors]

50-50 mix from a oxy-acetylene torch really makes them bark. You can't flood them, so you have to be really careful not to overpower the PVC. The shards are sharp. I have the scars to prove it. Also, ears of sweetcorn can be husked down to just fit in 2" PVC......

 

[PugetDude]

Bowling ball mortar:

8-5/8" ID x 1/2" wall x 20" long seamless steel tubing. 3" thick base plate with a 2-1/2" diameter x 1" deep tapered cup and 3/16" diameter fuse hole machined into it. Also welded a few gussets on the outside of the weld joint. Set it on fairly level ground (pointed a few degrees away from anything you value....)
4 ounces of black powder (smokeless won't work) will launch a 16# bowling ball out of sight.
Our best hang time was 21 seconds from detonation to impact.
The old black rubber rubber balls work best; 8.595" diameter, they are heavy enough to sit on top of the powder cup and compress the charge, then expand to fill the 8.625" bore on the way out. Air rushing past the holes in the balll whistle like a howling dog on the way down.

Don't think I have any pictures, we built it over 25 years ago. Used to get the bowling balls for a buck at St. Vincents or Goodwill.

Got the plans from an old gunsmith in Idaho- he built a smoothbore cannon that shot aluminum beer cans filled with concrete. He cast them with a rounded nose, they looked like oversized .22 shorts.

 

[Death Row Dave]

Machinist buddy of mine made one , 1 1/4 in bore , I see it finished . Next Monday he is cutting it up for scrap . I ask him “ WTH are you doing ? “ He proceeds to tell me “charged it up , Father in Laws barn was about 1000 feet away . Shoots a bar about a foot long . Jumps on the Harley to see the bar sticking in the barn . No bar on one side , just a hole . Goes inside the barn looks hole on the other side on the barn ! Thinks OH **** now . Goes outside , Family motor sitting there , hole through both sides , destroyed cabinets , TV , dishes , both sides of fiberglass camper . He could never locate the pointed bad projectile .

I have one looks very similar to Civil War era Howitzer , 6 in solid bar turned barrel , 2 oz black powder will launch a hard bar so fast and far it is never seen or located again .

 

[scooterbum46]

Machinist buddy of mine made one , 1 1/4 in bore , I see it finished . Next Monday he is cutting it up for scrap . I ask him “ WTH are you doing ? “ He proceeds to tell me “charged it up , Father in Laws barn was about 1000 feet away . Shoots a bar about a foot long . Jumps on the Harley to see the bar sticking in the barn . No bar on one side , just a hole . Goes inside the barn looks hole on the other side on the barn ! Thinks OH **** now . Goes outside , Family motor sitting there , hole through both sides , destroyed cabinets , TV , dishes , both sides of fiberglass camper . He could never locate the pointed bad projectile .

I have one looks very similar to Civil War era Howitzer , 6 in solid bar turned barrel , 2 oz black powder will launch a hard bar so fast and far it is never seen or located again .

You win........

 

[kaymccampbell]

Done properly, with a lot of very special ice cubes, you can make an annoying neighbor's new car look like it got carpet bombed by giant hail. Just saying. The entertainment value is amazing.

 

[TobeyA]

We used to play with simple PVC ones back in the day. Aquanet was our fuel of choice.

One day, I bought a bag of bamboo skewers and 3x5 note cards and made tail fins for the potatoes. About 30' out of the cannon they would settle into a nice spiral. Felt like it added about 20% to the distance.

For more fun, we would bury the capped end of a stainless pipe in a small bonfire. The pipe was perfectly sized to drop aerosol cans in. Those things would fly...

 

[bdbecker]

During my sophomore year of college, I was in a study group program for mechanical engineering. Basically, they would group 8-10 students together and we all shared the same core class schedule. A couple times a week we would meet as a group, along with a mentor who was a senior level student, and we could work through any questions we had about our classes. We also had a few design competitions between the groups. One of our competitions was to devise a way to launch an egg as far as possible without breaking it. The rules were very simple, basically no combustion like gun powder or aqua net could be used to propel the egg. Our senior mentor was super laid back and when we were brainstorming ideas, basically let us run with whatever as long as fell within the rules. On the day of the competition, most of the teams showed up with some version of a trebuchet or sling shot. One other team built an air cannon, but it was maybe 1/3 of the size of what we showed up with.

For a projectile, one of the guys machined a set of capsules shaped like a rocket out of nylon with removable end caps that had stabilizing fins attached to it. The egg went inside the capsule and was packed with grease. We then slightly pressurized the capsule with a few additional pumps through a grease zerk. First shot went nearly 1200 yards, but the egg broke. We dialed it back a lot for the second one because we wanted to win, and ended up posting a 500+ yard shot with the egg intact. The final shot we got out to 850 yards with the egg intact. The hardest part was digging the capsules out of the dirt - they would go 3+ feet into the ground where they hit.

Second place got out to something like 220 yards. One team tried to get us eliminated because we were using gasoline to power the compresserator, which was combustible, but they were just being sore losers. The program coordinator changed the rules after that year to make compressed air against the rules and placed dimensional constraints on the launcher size.

I'd also add... the campus police tracked my buddy down when they saw the launcher in the back of the truck and wanted to ask him a few questions about it. He ended up parking his truck at our place because they wanted him to get it off campus. Understandable.

 

[Monza Harry]

Were we all wearing the appropriate attire?
The "In My Defence I was Left Unsupervised" Tee Shirts
I posted a Pic but it was too small
Harry
Found one!

 

[laser3kw]

I saw "potato cannon" and had to stop in
Lot of great stories - reminiscent of days past - thanks to all

 

[gregs]

Machined a little cannon out of a piece of stainless well pump shaft. 3/4" bore and a small hole in the back for a piece of fuse. Pack it with a little gun powder and no projectile. Nice load bang. Usually set it off for new years or other special occasions.

 

[Modern Garage]

I wish I could remember how we came up with the idea, but we (my wife and I) figured out that if you break open a "brightstick" (the plastic tube that you snap and shake to produce light) and pour a drop or two of the contents onto the potato when loading it you can produce 'tracer rounds' that are quite entertaining to watch at night. Works best if you've cut the potato smaller to fit the barrel as the cut surface seems to absorb the luminous chemicals. For some reason we almost always used the potato gun after dark. Whether for cover or because that's when we reached the correct level of BAC I'm not sure.
Joe

 

[superspec]

Anybody want to throw up some plans… we’ve got plenty of compressor at work and we don’t have safety guys. I’d rather not use pvc though because I’ve seen what happens to them under high pressure.

Is google It but figure my GJ peeps will send me down a better path.

I think we have a piece of 8ft galvanized fence post at the shop, numerous propane tanks…probably everything w need except some plans.

 

[Richard D]

I built one to throw the large 4" tennis balls for my daughters dog. Worked pretty good except she wouldn't bring it back so I just had to go get her and the ball anyway.

New video · Saturday, Apr 18, 2020 🎬

Tap to view!

photos.app.goo.gl

Nice video. Rminds me of my Golden/chow mix who passed away a few years ago, loved to fetch.

 

[like2wheel]

Aaah the memories.
I nominate this for "Thread of the Year"!