Potato Bazookas

Zog The Undeniable writes "The latest craze in Germany is "Kartoffelkanone" or potato bazookas. These use hairspray ignited by a spark to fire potatoes at colossal speeds. The authorities are not amused." Everyone needs a hobby I guess.

Hardly new

[kramer]

We made one in our Physics class in high school. I'm due to go to my 10 year high school reunion in a little more than a year.

Home Depot.....

[alexc]

A guy who worked at home depot actually helped my friends create a potato gun.. Needless to say the advice he gave was great.

I had one...

[ruiner13]

I had one in high school. WE used to steal the electronic ignighters off of our neighbor's bar-b-que grills to create the spark. After testing every product, we found that starting fluid (basically ether) gave the best launches. The next best is that aqua net hair spray crap that everyone's grandma uses to make their helmet hair. Once, we even made a double-barreled one, which actually worked pretty well (seperate chambers and ignighters). I wish i still had pictures!

Do NOT stand in front of one, though....

[Doctor Fishboy]

My friends and I built a potato canon and regularly fired it over the skies over Tucson. It was fun to a potato hang in the air for up to 10 seconds at a time, and a bit of basic math estimated it to travel over 1/3 a mile. Beware though that the potato emerges at about 100 miles per hour (but slows down alomost immediately due to air resistance).

We stopped fiting it after we stuck a 1/4 inch thick board of plywood about 3 feet in front of the canon and fired away.

Damned if that potato didn't punch a perfect 4 inch hole through that board. As the potato emerged on the far side though, it almost completely stripped off the last ply layer from the board.

We gained a new respect for tuber-based weaponry that day....

Dr Fish

Re:Odd.

[Kalewa]

Especially not with one of these [frii.com].

When we were young

[rhadamanthus]

and stupid, we made several of these.

The most "impressive" one was a 6ft long black barreled cannon known as "black beauty". It had an ignition switch from a grill, eliminating more clumsy homemade solutions for ignition and could put a potato through a wooden fence from about 20 yards. It could fire them @150 yards on a good day. It was tremendously dangerous, with a 3 foot flame shooting out of the barrel each time you fired it. The heat and pressure on the piping caused it to crack and need replacement, a function often ignored by my more idiotic friends. Here in texas some younger kids at my church got caught firing one in a golf course not too long ago and recieved some fines from the local police. These things are not safe...

My last memory of that cannon involved modification to shoot sprays of water. Ignition, upon filling the barrel with water after placing a "separator" in the piping caused a huge spray of water and steam to eject in every direction. Took the bark right off of trees...

STUPID

Alternate... safer version of the guns

[Gaewyn L Knight]

We have done this for physics often... no explosives or flammables involved. (I know... where's the fun then :} )

All you need is a length of pipe that just barely fits a pingpong (table tennis whatever) ball through it. Fit a connector into one end of it that can hook to a vacuum pump.

Ok.. now here is the operation.
*WARNING do not have anything in line with EITHER end of this device!!! It is VERY unlikely but either end can give way and it fire either direction!*

Place the pingpong ball in the pipe. Place a single piece of plastic packing tape over each end. (Clear or brown... not filament!)

Use your pump and lower the pressure as far as you can. (You will have to expirement to make sure you can get it that low without imploding the tape on the ends)

When ready to fire.. put end with fitting slightly lower. Wait for pingpong ball to settle at that end of the tube. Aim. Using something sharp or pointed pierce the tape on that end of the pipe.

Bye-bye pingpong ball :}

Basically the inrush of air propels the ball through the tube and straight through the tape on the other end. We have clocked these pingpong balls in excess of 150mph :}

Please only do this under carefully controlled circumstances... It makes a great science expirement and is relatively safe. But as always be careful, wear protection and DON'T BE STUPID.

BTW You can pick up used vacuum pumps for cheap on Ebay... cheaper than 20 or 30 cans of hairspray so...

Re:Behind the times...

[sklib]

Another option is harnessing years of aerodynamics research and firing golf balls.

For added fun, take your cannon to the course!

Build one - chicks dig it

[Migraineman]

I built one years ago, and I must say that they're a blast. Make the barrel from 1-1/4" Schedule 40, as it's easier to find potatoes that'll fit snug. If you build a breech-loader with a threaded cleanout plug, make sure to keep the threads clean. Burnt hairspray and potato juice gets amazingly sticky.

I took the Mark-1 Potato Gun up to a local SCCA event for the weekend. Saturday evening we found an open spot and used a large billboard for target practice. The men all pounced on the opportunity to fire the thing, but the ladies were a bit hesitant. Given a little coaxing, they came around nicely (guys - this is your chance to put your arm around her and "help". Don't pass on the opportunity.) In the end, the ladies were more enthusiastic than the guys. That was okay by me.

Incidentally, go read the ingredients on a can of hairspray. SD Alcohol 40, Propane, Isobutane, and other combustibles usually top the list. Makes nice propellant. At sunset, you'll get a really nice light-blue alcohol muzzle flash coming out the end.

Ensuring peace through superior firepower ...

Re:Hardly new

[nanojath]

I prefer the slightly less ballistic CO2 powered version - Although it takes a quick and steady hand: drop a chunk of dry ice into a plastic soda bottle , add water, cap tightly, drop down the pipe (we used PVC set in concrete in a gallon ice cream bucket)quick shove down some newspaper for wadding followed by the ammo - a cylinder of ice frozen in a can. Of course, I live in Minnesota where preteens and drunken farmers roam the countryside with rifles and shotguns come hunting season, so I'm possibly more blase about this kind of thing...

Re:Odd.

[andrew_0812]

That's exactly what I was thinking. Germany needs to get with the times, American youths have been making these for years. They aren't even that popular anymore.

Re:Behind the times...

[Dr Caleb]

The arrow went right thru the sheet of plywood he was aiming at...

I just use my bow for this kind of a task. When my bow is cranked to the full 87 pounds release, I can put a 2317 Easton shaft through 1/4" Lexan, up to the fletching. Any smaller arrow (2217, 2316) and the arrow explodes on impact. Nasty!

Playing with fire

[babbage]

Heh, I remember these. My sophomore year of college, several of my friends got into building potato guns. They'd all build their different guns and fire them out the window of one of the dorms, where they could arc through the air & land in a soccer field a quarter of a mile away -- scaring the bejezus out of anyone that happened to be walking around in the process :-)

Building the things was pretty simple -- all you need is a strong tube, a projectile, propellant, and an ignition system. As others in this thread have mentioned, my friends' ignition of choice was the ignitor from old BBG grills. This worked fairly well -- you actually get a trigger to work with -- but they always seemed to break down after a while, so the design had to be built such that you could swap out the ignitition every now and then.

That is how Jeff burned his damn face off :-)

See, like I say, everyone would just sit around in their dorm, building these guns and preparing their next shots. Jeff was about to shoot his when, wouldn't you know it, the ignition jammed. Bummer. So as usual, he unscrewed the back to get at the ignition to check on it. Unwisely, this involved taking a look into the ignition chamber to see -- well, the back end of a potato & some invisible ether.

Did I mention that? I guess not -- their propellant of choice was ether. I have no idea where they got the stuff, but damn it was good for making a nice little controlled explosion. Or in this case, uncontrolled explosion.

So anyway, there Jeff was staring into the back end of the gun, when somehow he bumped the trigger.

And it went off.

And the ether exploded.

Remember how when you were a little kid, and you liked playing with the garden hose in the summer, but your evil older brother (that would be me :-) would hide around the corner pinching off the flow, and you'd get confused and look into the hose trying to find the water -- and just at that very moment that bastard of an older brother would uncrimp the hose and blast you in the face?

This was a lot like that, but with fire instead of water.

So anyway, there Jeff sits, with a ball of fire around his head, and well you get the idea. I wasn't actually there when this happened -- I was back at my dorm, probably cowering under the bed from my psycho buddies (or reading email more likely...). But Jeff was my roommate and, about five minutes after the incident, Jeff comes staggering back to the room. He has no eyebrows -- just white molten lumps where they used to be. He has no eyelashes. Or rather, he does have some remnants of eyelashes, but they are half an inch long each and there is is a six inch line across the front of his hairless brow. And exactly in the middle of his (now apparently sunburned) forehead is a bright red circle -- as if someone had thrown a tennis ball, dripping with paint, really hard at the middle of his forehead.

Jeff took a little nap at that point. He woke up a day or two later, ordered some pizza, ate, and went back to sleep. He slept for most of the next several days, it took a couple of weeks for the tennis ball spot to fade away, and it took a month or more for the hair to grow back. He wore a hat a lot those days, IIRC :-)

So, let this be a lesson to you spud projectionists -- the back end of the gun is just as dangerous as the front!

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Re:Odd.

[devilbat]

I made one of these out of schedule 40 PVC tube from Lowes. Propellent is Aquanet and it's ignited with a grill starter wired to a lawnmower sparkplug. Still have it it's in my garage. 6ft long projects a potato at a little better than 200mph. The power of these things is pretty shocking actually. I cut one of the potatos in half and put a nice big rock in front of it. Kinda used it like the wadding in a shotgun. I shot it at an old steel lawnchair. The rock went right though it. Although I haven't done the calculation I would bet $1 that the amount of energy delivered from one of these potato guns is higher than a .45 or probably any other pistol this side of a .44 mag. Make one of these, get 25lb of potatos. You will giggle for hours.

Potato intifada?

[Tirs]

How come Palestinians didn't discover this yet? They are in dire need of cheap weapons!

Oh well, probably there is no hairspray in a place where all women wear their hair covered.

i made something similar...

[trybywrench]

in high school. Took a bunch of the smaller coffee cans and cut half moons in the bottom. I then duct taped about 5 togather alternating the half moons. Last I punched a nail hole in the bottom can. You poor about a half cup of alcohol in the top and shake the whole thing until all the surface area is covered then give it a minute so that the alcohol can evaoporate. Stick something in the top ( plastic gatorade bottles worked well ) and strike a match near the nail hole. It was very very loud and powerfull. The last time i ever used it I set everything up like I'd done a hundred times before but when I put the match next to the nail hole the whole thing went off like bomb ( I think it was a taping failure)! The detonation was so loud and violent that I was completely disoriented for about 30 seconds. Then the realization that I prolly have invisible burning alcohol all over me and I couldn't feel my hands brought me back to reality. A check for hands/fingers and burning sensations soon followed. I haven't touched it since ( about 8 years ago ).

Re:Good point.

[Kymermosst]

Ahhh the days of design tech.

I designed a pneumatic gun with interchangeable barrels that was designed to fire anything from a shooter marble all the way up to a roll of toilet paper.

Dual pressure guages, expandable air chamber, positive-pressure locking system, and one-way airflow between the firing pressure chamber and the main air chamber.

Paint sprayer parts make the bulk of the guts.

Ahhh.... I really should finish putting it together. It'd be great to actually fire it. I wanted muzzle velocity to exceed the speed of sound.

Potatoes are for wussy germans

[dmeeking]

How about launching a 10lb pumpkin 4000 feet? http://www.cannon-mania.com/pumpkin_chunkin.htm [cannon-mania.com]

The legality of it all...

[jlrowe]

A little thought applied to the 'spud' gun and how easy it is to make is instructive if applied on a larger scale.

Bear in mind that in some places, I think California and Britain, laws have been considered to ban spud guns. You can make a law to ban anything, but practice show here that it is *easy* to make a gun out of whatever is available.

Yet though it is easy and a lot of us here have made them, no one here shot anyone and killed them with it. No laws or punishment is necessary because there is already a law against killing someone. You only have to punish those who break the laws of nature, killing or maiming someone and the destruction of their property.

Likewise, we don't need any gun laws at all. We already have one in the US called the 2nd amendment, plus the various laws based on the 'natural law' above.

Like spud guns, which can indeed kill and maim, guns which shoot lead bullets (and spud technology could...) can easily be made in a workshop, and sophisticated guns can be made in a machine shop. It is so easy to do, that is cannot in reality, be controlled. Nor is is a bad thing to avoid controlling it. We just have to enforce the 'natural law'. And punish the perpetrator, not the inanimate object.

Spud Guns Do Not Kill.
Nor does a Smith and Wesson.
The bad guy kills.

Do NOT Try This At Home

[SuperJames_74]

One of my co-workers made an extreme potato howitzer [barr-fam.com] when he was younger. This friggin monster runs on ether and has an automobile ignition system! Do NOT try this at home!

Re:Frozen... that reminds me.

[ReTay]

It is fact they were/are trying to devolope a canapoy that will deform instead of break under a bird strike. It is an air cannon that they fired chickens at test caniopies to simulate landing speeds. As far as sucking one into an enjine (no as funney as it sounds if you are in the plain at the time) It mostly just trashes the engine. But with single enjine craft (Falcon) that is enough.
The real answer is to find out how to keep them from landing on runways. Or tring to nest near them.

Fun at work

[toolafial]

My father worked at a coal mine. Every year they had to replace the CO2 cartridiges in the mining equipment. The CO2 cartridges were used as propellent in the fire extiguishers, so they where pretty powerfull. The old catridiges where perfectly good so what they would do is take a 2" metal pipe with a nail in the bottom and use that as a mortar. The cartridegs would regularly fly 500 feet over a mountain near the mine. Plus we built potato guns as kids. We had one kid hit a cat at a 100 yards with one. It didn't kill it, but the cat never came around his house again (it was a stray).

Re:Firing chickens. True story.

[Splab]

Heh, isn't this an urban legend?
I've heard it was NASA doing test to make sure the windshield woulndt get smashed upon reentering and hitting something airborne. Part about the british airways is the same except they send an email with the 3 words:
"Thaw the chicken!"
Anywho It's always a good laugh