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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.
That doesn't make them any less fun, though. For Xmas I got Backyard Ballistics which documents how to create a potato gun as well as many other loud and violent ballistic weaponry for children of all ages. Highly recommended.
For anyone interested in doing this too, building instructions can be found here
giel.y contains 2 shift/reduce conflicts
Not like no one else has done this on the net. Here are detailed instructions (at least enough to build) if you are so inclined... http://blizzard.rwic.und.edu/~nordlie/cannon/
Old, but very sweet!
GotSpud?
Tony's page
Spudweizer
Simple Spudgun
My mom would never let me build one when I lived at home, so now's my chance. AND, I'll be prosecuted as an adult, and possibly an 'American Terrorist'
I find it's easier to simply get a matching diamater chunk of potato and put it in the freezer for a day :)
frozen oranges are good too if you've got the right diamater pvc
Send lawyers, guns, and money!
the story calling it "craze" is somewhat overrated. At every time in the last 50 years, kids have built something that goes boom. I think that is the same in every other country.
I live here and i haven't seen or heard of a single "Kartoffelkanone" prior to the article and the photos of the SPIEGEL magazine.
At least it's an interesting method of delivering mashed potatoes.
Yours, Martin
It just so happens I had this same hobby a few years back. Except we used propane as the fuel and golf balls as the projectiles. Tiger Woods beware! It was truly amazing to see a golf ball launched several hundred yards, almost out of sight. For those interested, www.spudtech.com has a load of information on these fun toys.
Scott
Other good ammo is taking a bunch of D batteries and duct taping them together. They are excellent for taking out street lights.
Hairspray is for wimps...real men use compressed air. Compressed air is much more powerful, you don't have the legal ramifications of using an explosive, and it's cheaper than hairspray. It takes a little more work to get it air-tight, and you have to buy a thicker PVC pipe, but the results are worth the extra effort.
Public use of any portable music system is a virtually guaranteed indicator of sociopathic tendencies. -- Zoso
No, german kids have always been building things that go boom, as did kids all over the world. It is the german magazine DER SPIEGEL which discovered the topic and decided to make it an issue just now. Seems to fit with the overall mood, US going to war in Irak and weapons inspections and all.
Kristian
Check out this story we ran over on Sci-Fi Today which included some relevant links. You can get Sci-Fi Today daily headlines on your Slashdot home page by clicking here and putting a checkmark in the Sci-Fi Today box. Or heck, just join us as a member and help us build a science-oriented discussion community!
even better, acetylene. any hobby store sells calcium carbide (the stuff in old miner's helmets to make the light). just put a little calcium carbide in water and you have instant acetylene (used for welding). ignite that with a gas grill ignitor and you can easily have potatoes going 150mph. when i was little my brother and i experimented with many different style guns. the best we came up with was using acetylene as the propellant and using a 1 inch pvc barrel (rahter than the traditional 2 inch). you couldn't shoot a whole potato with it, but the part you did shoot went about 150mph. (we figured that out by timing how long the potato stayed in the air when shot vertically).
www.kartoffelkanone-forum.de
Here's a letter from the ATF regarding the legality of the "spud gun". Note the date - September 12, 1995.
Definitely old news...
Life is the leading cause of death in America.
It sounds like these have gone from "geek hobby" to "mainstream danger"
Good thing most of these kids are probably too stupid to make a pneumatic spudgun. Far safer for the operator, but FAR more dangerous for people at the wrong end of the cannon. (Pneumatic spudguns use a constant pressure for most of the firing cycle, rather than the quick spike of pressure from combustion. As a result, pneumatics can pack a LOT more power into a gun while stressing the components less.)
retrorocket.o not found, launch anyway?
I remember back about 25 years ago when pop cans were more substantial, made of tin, and just the rights size. My cousins used to cut the tops and bottoms off 5 or so cans, leave the bottom in one, black tape them all together, drop a fuzzy tennis ball in, inject lighter fluid at the bottom and add spark. Works until the fuzz is rubbed or burned off the tennis balls -- you need the fuzz to get a good seal. The nice part of this is that you don't have as much back pressure as with a potato gun. Though I have seen potato guns go hundreds of yards.
Down in Dunedin FL, there is a local museum dedicated to Police and the Military. http://www.naslemm.com On display is a spud gun manufactured by the engineering department of Smith & Wesson over 20 years ago. Big, Blue and with the S&W Logo, a bit more impressive then the tennis ball cannons, I used to build back in the 70's.
We played with these a lot as kids. Aqua-Net + potato + sober people, no problem. Firing them with ether is bad [weakens the PVC cement after a few firings and gun explodes], other non-squishy projectiles are bad [jam in the barrel and gun explodes], and impaired people of course don't mix well with firearms.
Get with the times PVC pipe connected with pvc cement removes the chances of flying metal shards Also: Deisel engine starter contains 90% ether which will over double the range of a hairspray fueled gun Lastly: a Grill ignitor works far better than a battery Silly Germans
Since, to my knowledge (IANAL), in the state of Texas these things are banned because they can be considered a firearm (some lame excuse of combustible material). So my brother built one using a sealed chamber with a ball valve. He uses a bike's tire pump to pressurize it, and even has a gauge built into it. The cool thing about this on, you can load anything including water. At about 70 psi, it could shoot a ping pong ball (filled with water) about 100-125 yards.
To provide information so that needless accidents like this do not happen in the future, I present the quality ingredients necessary to build a safe, fun spud gun... Lord knows you're just going to be provoked to do this anyways, so might as well do this right and safe. As usual, you are at your own risk, so I assume no responsibility for your stupidity in embarking on this venture...
Ingredients...
1. 1 2" X 3' long piece of PVC Tubing.
2. 1 2" PVC "T" Joint.
3. 1 2" X 8" long piece of PVC Tubing.
4. 1 2" to 1" Reducer Fitting.
5. 1 1" X 4" long piece of PVC Tubing.
6. 1 1" PVC Tube Cap.
7. 1 3" to 2" Reducer Fitting.
8. 1 3" X 1' long piece of PVC Tubing.
9. 1 3" PVC Screw-On Drain Cap.
10. 1 1 Coleman Lantern Igniter.
12. 1 3" Grinding wheel for grinder.
11. 1 Small container PVC Cement.
12. 1 Broomstick handle or like equivalent.
Procedure:
First, a word about cementing... Get the type of PVC cement that has the little ball in it and is kind of runny... There are many types, but good ol' Ace PVC cement does just fine... Also, make sure to cement all of the available surface area of the joint... Don't be sloppy, but don't skimp, as this is what keeps your head on... Additionally, when finished with your project let it sit and DON'T flick the flint! The vapor is quite flamable, and you want it to fully cure at room temp, not to mention it'll put a 3' flame out the other end when you do flick it, burning your furnature, etc... so be patient and wait... OK, now for the fun stuff.
Bevel the end of the 2" X 3' PVC Tube. This allows for good shearing of the potato and prevents excessive pressure buildup from wedging. I just put a Makita grinder in a vice (gently) and beveled the end on the edge of the grinding disk... Note: this is kind of a no-no (nonferrous things on grinding stones are bad), so THROW THE DISK AWAY WHEN YOU ARE DONE WITH IT! This is why I don't use a grinding wheel instead of a stone... Cheep!
Cement the unbeveled end to the 2" "T".
Cement The 8" section to the other end of the tube.
Next, put the 2" to 1" reducer in the bottom section of the T.
Cement the 1" Plug to the 1" tube and cement the other end into the 1" reducer Plug... Now it kinda looks like a gun.
Cement the 2" to 3" Reducer to the other end of the 2" X 8" (unbeveled) section.
Measure the depth of the 3" Drain end cap section (unthreaded end) and draw a line on the 3" X 1' section that corresponds to that depth (do not test fit... they won't come apart).
Then drill a hole about 1/2" past the mark you just made on that tube. This hole should be smaller then the threads on the flint mechanism. Idealy you should use a drill bit and tap that corresponds to the thread of the flint, but you can thread it with a bolt with the same thread as the flint (Most designs thread from the inside... if yours threads from the outside, pitch it and get one that threads frome inside, as it is safer this way).
Drill the hole, tap it, and then take the flint mechanism apart in a fashion that you can thread it in to the hole from the inside (open end works great here). It is usually best to keep as much of it assembled as possible, as its a bear to add flints once its together (it can be done, however). Make sure that the flint points so the spark path points to the screw cap... this produces a better flame front and prevents potato shreds from gooing the flint.
Finally cement the drain Plug end to the marked edge of the 3" section (next to the flint. Leave the cap off, so things can air out once its done.
Get the gun section you were working with before and cement the free end of the 3" PVC tube to the reducer in a manor where the flint is perpendicular to the handle and so it is on the side you use to write with (your preferred hand).
From this point you wait the max full-set time for the glue you bought (not 5 minutes, like 48 hours or so), Its on your glue container.
After this point the rest is self explainatory, (broomstick shoves potato to ridge in "T") So have fun and use with proper gun ettiquette, as this is essentially about as dangerous.
Options... (realy stupid ones) Use ether (I like Pyroil, it has upper cylinder lubricant!) instead of hairspray... Its more finicky, but is cleaner and whohoo what a kick when it works! With ether you spray the cap, not the chamber, so be careful, and use it sparingly, as not to have it run past the threads...
Good Luck, and pitch the gun when the flint wears out, as the joints eventually will break down under heat and pressure... Keep it safe!
The guy who got one in the eye was hit by an apple. So that was shot from an apfelkanone, right?
If Slashdot were chemistry it would look like this:Cadaverine
If they get their hands on this then we may have a problem.
Isn't this how the great Irish potato famine started?
"Giving money and power to governments is like giving whiskey and car keys to teenage boys." - P.J. O'Rourke
I'll second the warning to be very careful with potato guns. A kid in my old neighborhood was badly injured when messing with a gun made from a chain-link fence post. Don't know exactly what he was doing with it, but he came very close to blowing half his arm off. I never heard what happened to him afterwards...hopefully the doctors were able to reattach it.
Moral: Be very careful when you're messing with stuff that explodes...
DennyK
is the Lost Finger
My semi-literate, tv-watching Playstation-playing lazy step-brother (who is no releation to me) has had one of these for years.
He liked to fire it around the neighbourhood. He used PVC pipes. Bright kid.
I wouldn't be overly concerned, unless they get into an SS uniform and say they are Panzerfaust.
ABS (black) tubing is typically sold in plumbing stores for low pressure sewage applications and in my experience has not been as safe as PVC tubing. I had a friend who in college had a ABS potato gun explode in his hands. His hand ended up in a cast for a few weeks and his hearing was pretty messed up for a while too. I believe that he was using a hairspray based propellant at the time. He thinks he tamped the potato in too tight before pulling the trigger.
... maybe I've just been incredibly lucky.
I have to agree that the carbide+water fuel is the best I've encountered - cleaner, more powerful, and more reliable than any hairspray-type propellant. I've used this successfully many times in PVC cannons with no detonations. I always bought the thicker walled PVC designed for high pressure. PVC does produce some pretty sharp shrapnel when it does blowup
Inflammable means flammable. Nitrogen is inert, as is CO2.