Potato Bazookas 672
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.
These have been around for quite some time (Score:2, Informative)
Building instructions (Score:5, Informative)
For anyone interested in doing this too, building instructions can be found here [lycos.de]
or for an aliternate site... (Score:5, Informative)
I'm making one when I get home (Score:5, Informative)
Old, but very sweet!
GotSpud? [gotspud.com]
Tony's page [tommasi.org]
Spudweizer [tripod.com]
Simple Spudgun [mshamash.com]
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'
Re:Behind the times... (Score:5, Informative)
frozen oranges are good too if you've got the right diamater pvc
Overrated (Score:3, Informative)
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 [spiegel.de].
At least it's an interesting method of delivering mashed potatoes.
Yours, Martin
hair spray is for wussies (Score:5, Informative)
Re:Behind the times... (Score:2, Informative)
Hairspray is for girls (Score:5, Informative)
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.
Re:Behind the times... (Score:5, Informative)
Kristian
Additional Relevant Links (Score:3, Informative)
Re:I had one... (Score:5, Informative)
Another pick (Score:3, Informative)
Obligatory letter from the ATF Re: Spud Guns (Score:5, Informative)
Definitely old news...
Good point. (Score:5, Informative)
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.)
Re:Hardly new (Score:1, Informative)
A local museum has one by S&W (Score:4, Informative)
safety (Score:2, Informative)
Hairspray and Masking tape? (Score:2, Informative)
Re:Hairspray is for girls (Score:5, Informative)
From testing I found an air cannon with a piston quick exhaust valve has about the same performance as a propane/air cannon of the same size when the air is operated at about 40-50 PSI. At 100 PSI it is no longer a contest. For some reason the propane cannon is much noiser, but the air cannon is much more powerful.
A friend and I did a comparison about 2 years ago. Both cannons had 2 inch barrels with an overall length of about 8 feet. The air cannon used a piston valve 2-1/2 inches in diamater that directly seated on the 2 inch breech of the barrel inside the air chamber. This provided an air orfice the diamater of the barrel. Look up quick exhaust valves for details of the valve operation. The 8 foot length in both cannons is a safety feature. It's almost impossible to get any body part over the end of the barrel while operating the trigger mechanism.
I prefer the air cannons for safety reasons. They can be hydrostat tested so you know they are not likely to blow up when used at about half the test pressure. You just never know with a combustion cannon. As always, follow some safety guides including pressure testing and ensuring the downrange is clear. My current pnumatic is tested at 150 PSI and operated in the 60-80 PSI range. Holes in 3/4 plywood are no problem to make.
A roll of adding machine tape shot into the sky is a sight to behold. It unrolls on the way up and tears into dollar bill size pieces until it looses enough speed to unroll the remainder without tearing. It's a confetti storm of dollar size pieces with a 60 foot streamer at the very top. It's also realtively safe if used in an area with lots of spectators. There are no heavy high speed objects falling out of the sky to injure a spectator. The 8 foot length pointed up keeps onlookers from trying to look down the barrel while charging. It's best to eliminate the plastic core from the roll of paper before use.
Air-Pressure Potato Guns (Score:2, Informative)
Spud Gun Smarts.. Or How to Make a real spud gun.. (Score:1, Informative)
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!
Truth in labeling (Score:3, Informative)
Re:Odd. (Score:2, Informative)
Isn't this how the great Irish potato famine started?
Re:Safety First. (Score:3, Informative)
Moral: Be very careful when you're messing with stuff that explodes...
DennyK
my favorite (Score:1, Informative)
These are old... (Score:3, Informative)
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.
Re:I had one... (Score:1, Informative)
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
Re:National vs. State (Score:3, Informative)