Although the behemoth known as a spud cannon is fun (see below), I also like the smaller, and safer, eponymous device which is basically a squirt gun except that you load it by shoving the tip into a potato, and you fire it by pulling a handle which compresses the air within the chamber enough to expel the little bit of edible starchy tuber. Not nearly as satisfying, but it's great for doing live-action Quake, namely because it won't actually kill anyone. It is to a blaster as a spud cannon is to a railgun.
Real-life Quake could be fun...
Also known as spud guns, these are frighteningly easy and cheap to make. My brother and I made one by taking a 3"x2" 'why' PVC junction (used to attach a 2" PVC pipe to a 3" main), putting about 3" of 2" PVC in the branch, putting a cap on the end of that, and affixing a Coleman lantern flint into the length of pipe. This became the handle and trigger. For the back of the 'why' (which is the mixing chamber), we attached a cleanout adaptor (used to attach a screw-on cap for the purpose of, well, cleaning out the pipeline), as well as a screw-on cap. On the front, we put a 3"x2" flange bevel (allows you to put a 2" pipe into a 3" fixture), and about 2.5 feet of 2" pipe into the bevel. Before attaching the pipe, we cut a pair of notches in the end and put a cut-off nail across it (this serves as a stop to keep the ammunition from falling into the mixing chamber). After that, we filed the tip of the pipe, making it sharp, so that it could cut a potato. Everything gets sealed tight (except the end cap, which needs to come on and off). We also took an extra piece of 2" pipe, cut a square hole in it, and attached it to the wrench-hold on the cap so that we could put it on and take it off more easily.
To load: shove a potato onto the end of the muzzle, turn it to cut it, and push it downwards until it's a round chunk in the barrel. Use a long stick (such as a broom handle) to gently push it down until it hits the nail. Turn it over, open up the back, spray in cheap hairspray (I recommend Aquanet, as it's cheap and very high in propane) for a few seconds, immediately cap.
To fire: aim, then with a flick of the wrist, spark the lantern lighter. You should feel a satisfying recoil, hear a resounding pop, and see a chunk of potato be propelled at about 120 MPH into low-earth orbit.
Great for ringing in the new year/millennium.
In the good old days, you used to be able to make your own Ethnic Cannon out of beer cans and lots of duct tape, because beer cans were made of steel. DO NOT use aluminum cans, as the explosion required to launch the potato on its flight of glory will blast straight through the crappy aluminum like a hot potato through butter. If the idea of making your Ethnic Cannon out of cans is just too appealing to you, go to an Asian foods market, as many Asian softdrink companies still use steel cans. Otherwise, use a fiberglass tube.
If you want to have Phun With Physics, get yourself a plastic gallon icecream bucket. I recommend Blue Bunny. If you do not live in a country with gallons, just find a large icecream bucket. Maybe 2 or 3 litres, or so. Anyway, turn this bucket on its side and attach 2 ring hooks, one near the top, and one near the bottom of the bucket. Tie a piece of rope to each ring hook, and attach the other ends to a beam, or the ceiling. Something that is solid and not going anywhere.
==o===o== Beam | | | | Ropes (3 ~ 4 feet) | | |-o---o-| Top | >(:x) | Bottom |_______|
Now, set up some sort of grid on a large sheet of paper or a blackboard, and hang the bucket in front of this grid from a side view, as shown in the diagram above. Now, pack the bucket full of insulation, you know, that pink stuff in your walls. This will keep the potato from smashing through the back of the bucket.
Now gather your friends or students around to be observers. As the potato exists on the macroscopic level, the laws of quantum physics will have little effect, so this should not change the result. Get one person to aim the cannon into the bucket. Have this person level the barrel of the Ethnic Cannon with the center of the bucket, with the end of the barrel of the gun about 4 or 5 feet from the mouth of the bucket.
DO NOT hold the cannon bazooka style, on your shoulder, instead, steady it near your waist, like Rambo with an automatic rifle. This way, if the cannon does explode, it will not destroy your head, but will only sterilize you as bits of Ethnic Shrapnel and flaming potato lambast your genitals.
Fire the cannon. Your observers should watch the bucket swing back and up on the ropes like a pendulum. Have them note which grid mark the bottom of the back end of the bucket reaches. You can now estimate the force created by your Ethnic Cannon.
As a neat little bonus, the rapid accelleration of the potato by the Ethnic Cannon, followed by the rapid decelleration by the insulation-filled bucket will cook the potato nicely. I wouldn't recommend eating it, since the potato will also probably have little insulation fibers sticking out of it.
Thanks to Jerry Wilkes, the most awesome physics teacher ever. Have a happy retirement.
Potato Cannons, commonly refered to as spudguns, potato guns, etc, are typically made of two pipes, one being a reaction chamber and one being the barrel. The potato goes down the barrel, and the chamber is filled with Aqua Net hairspray or WD-40 or something like that, and it is ignited by a barbecue ignition.
THERE IS A BETTER WAY, FOLKS!
I will now tell the story of my friend Richard and I.
Its our senior year of high school, in I town I commonly refer to as Pleasantville, or Hell, and we're both on our school's ASB. We come up with the idea of shooting candy and t-shirts into the bleachers at the upcoming Renaissance assembly. The advisor liked it, and told us to spend whatever we needed to get it done.
Kick Ass.
We set to work. Richard gets ahold of a small 3000 PSI rated fire extinguisher for real cheap, and we set out to Ace Hardware to buy parts. A nice four foot length of PVC did nicely for the barrel, and that two foot high pressure air hose looks nice also... A couple of bushings here and there, and we're out of the store.
We are lucky enough that every sprinkler manufacturer in the world is located in our town, so we head down and buy a $90 solenoid valve rated up to 250 PSI. wow...
Radio Shack is next. Some nine volt batteries, wires, buttons, lights, and a project case and we leave. Back to Richard's garage.
If you haven't already figured it out, we mounted this fire extinguisher case onto my back, put the solenoid in line with a pressure gague, attached it all together with the electronics, and attached a barrel with a nice round button on the end.
Taking an air compressor, we hooked its hose to the fire extinguisher, filled the thing with compressed air, and had a very nice projectile weapon in our hands.
Sure, we used it at school at like 40 PSI, shooting candy and t-shirts into the crowd... but that thing shot a potato three times as far as ANY WD-40 cannon I've EVER seen.
A couple of neat little tricks to try.. Load the barrel with some powdered and mixed thick mashed potato solution, sit in the back of a truck, have someone ring a doorbell as you aim.. They open, you fire, mashed potatoes everywhere! Drive away as quickly as possible. Also, get some of the same pvc pipe you used to make the barrel, and cut off about four or five inches, fill it with water and freeze it. That thing will go through a brick wall.
Have fun, don't get hurt, and know that air pressure kicks ass!
THIS IS PROBABLY A BLOODY SILLY THING TO DO, SO IF YOU DAMAGE YOURSELF WHILST DOING THIS DON'T SAY I DIDN'T WARN YOU
1 x PVC spaghetti tube (tall cylindrical tube used for storing spaghetti) 1 x large can of hairspray 1 x rolling pin (or any suitably stout prodding device) A quantity of large potatoes, and 1 x gas hob (preferably one that can be rigged up outside)
Construction and Firing
I've only ever seen this monstrosity constructed once, and it managed to fire a reasonably large spud high enough to bounce off the roof in a TV studio, so I'd advise you didn't let it off inside unless you want to knock a hole in the ceiling
Sources include My memory of an episode of Jeremy Clarksons chatshow broadcast a couple of years ago
printable version chaos
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