Miroslav

Anyone ever shot a potato gun.. Just made one and these things could kill someone.. Its made from PVC pipe.. Has a 4" chamber and a 2" barrel.. spray starter fluid into the chamber and with the help of a built in flint.. put the cap on.. flick the flint and boom. There was a story on the news on some kid putting a bullfrog in it instead of a potato and shooting his friends eye out..

tropple

Early in my career as a Navy aviation electronics technician, I worked in an F-8 squadron in San Diego.

I remember one long boring night shift when we made a cannon out of coke cans and tape. We used alcohol for propellant and fired a couple balls made from masking tape and self-vulcanizing rubber tape wrap. The damned things flew across the hanger width and made big sooty blotches on the far wall about 60 feet up.

The third time, the cannon blew up creating the most amazing fireball that rose to the level of the windows at the top of the hanger where the squadron offices were located.

Needless to say, the squadron duty officer and asdo and PO of the watch all ran out to investigate the fireball that lit up the duty office.

When the panic died down, the night check maintenance chief about kicked all of our asses to hell and back.

Since then, I have never been tempted to experiment with any type of artillery. I prefer my potatoes in salad.

I was working a project a couple years ago in Denver and saw a couple guys shooting a potato cannon outside their building. It was pretty spectacular. The potato went a couple hundred yards, easy. After the first bounce, you couldn't see it, it was so far away. It was most impressive.

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MooseMan3000

Yeah, my brother and I made a potato gun, much like the one you described. We brought it to a large, deserted field and shot the potatoes off for our dog to find. It's a good time.

MSD

What are the lengths of the chamber and barrel? What sort of range are you getting, and with what size potatoes? We need more details, and, if possible, video clips.

I'll try to get a few clips of mine up, it's a sinister contraption made entirely of iron pipes forged in the depths of hell (my basement) that shoots large (1") gumballs hundreds of yars into the night.

Also, if you let the potatoes dry out a bit and spray them with your fuel of choice, they'll fly out, engulfed in flames.

MooseMan3000

My cannon was about 3.5 feet, overall length. The chamber was roughly 4 inches, if memory serves correctly. We got about 200 yards with medium-large potatoes (it was about a 2.5" diameter barrel), and using WD-40 as a propellant.

If I still had it, I would film it for you. Heh, maybe this is a good excuse to build another one.

DelayedReaction

Compressed air is typically safer and easier to control. There's a decent number of websites out there that give you advice on producing proper potato projection.

Just be careful. Anything that can send a potato the length of a football field can easily send you to the hospital.

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BoomTruck

I have built several pneumatic and combustion guns. John Deere starting fluid works best in a combustion gun. (minimum 80% diethyl ether, as opposed to 40-50% for the cheap stuff).

A properly set up pneumatic launcher can move things a lot farther. But I would recommend building a scatterblanket around the chamber in case something went wrong. I used the legs off of 3 junk pairs of jeans and about 2 rolls of good duct tape on my first gun, and it held when a glue joint failed at 110 PSI.

I would also recommend filling them with water before charging them with air for the first time. if it does fail, the pieces won't go flying all over ground zero- I mean the test site.

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cheese

Pfft potato guns? Try Bowling ball cannons

http://www.docsmachine.com/nonPB/mortar

tropple

Wow. I would love to have a bowling ball cannon!

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jaco

just a tip, use sch 80 PVC, not the thinner 40 when you have to use pvc as the material. probably triple the strength. I also suggest you listen to boomtruck about the scatterblanket, amazing how little things can go wrong with explosives and fire.

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JStrider

i made a potato gun...

has a 6 inch diameter chamber... a littler 30ish degree joint piece... with a screw on cap on one side... and a 2 inch barrel on the otherside...

the barrel is about 4 feet long... made out of the same pvc... and i beveled the edge so its sharp and the potatoes are cut to seal in the barrel when i jam them in...

and then i use a lantern sparker to light the fuel

fuel i use butane from an aerosol can... works great... and doesnt gum the chamber up like hairspray...

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farmer goo 2005

hmm homemade cannons�@�@�@hehe we made a cannon out of pvc that was designed to shoot batteries. The barrel was 20 feet long and it was pneumatic. After all the calculations we did we discovered that it had the potential to shoot just under 2 miles! So needless to say we never fired the thing due to the fact that you have no way of knowing whats 2 miles out in the field but it was an impressive cannon none the less.

JStrider

.... .... ...

how did you keep the barrel from flexing?

.... and couldnt you just aim it slightly at the ground?

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sailor

We had one we used to take on camping trips with us. A simple thing, made of PVC with a lantern starter. It sure as hell shot well though--we used to launch large sized dinner potatoes a few hundred yards. The thing held together pretty well too, barring a couple times when the end wasnt screwed on tight, causing it to fly out the back when it went off.

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Bossnass

I've made a couple of each combustion and pnematic types. Great fun. My switchback pnematic model did 200+ meters at 70 psi with a good sized spud. I haven't dug any out for a year or two... maybe I should do just that.

Rodney

My brother-in-law and his friends made one just like this, maybe a little longer in the barrel. He and my sister have a house on the water, and one Thanksgiving day, after dinner, we all went out on the deck and watched them shoot potatoes out over the bay. They're all firemen, go figure.

JStrider

mentioning water...

one thing thats waaaay cool to do

get a couple gallons of water

prep the gun like normal... make sure the potato seals extra good
pour the gallon of water down the barrel...
fire...

ive also seen people put a french fry carton down the barrel to make a shotgun

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tropple

Oh, holy crap:

http://www.onnnews.com/Global/story....0&nav=LQlCOESX

Judd Coffey is listed in critical condition at Miami Valley Hospital in Dayton. Twenty-two-year-old Jason Anderson is listed in fair condition at Miami Valley_Hospital._ The condition of 48-year-old_Robert Kiser...

I hope that these guys aren't from here!

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titty twister

I still have the combustion model I built a while back. First off...BoomTruck....good idea. Scatterblanket could save your ass.

On to the spudmaster....

2" PVC for barrel ~ 3 feet long.

4" PVC for chamber ~ 1 foot long.

4" to 2" reducer in the middle.

On the end of the 4" chamber, a threaded end w/ a sewer line clean-out cap.

For fuel, I drilled a 1/8" hole slightly into the chamber, followed by a 1/16" hold all the way through. During combustion, this hole is so small it hardly matters. This hole is where you stick the business end of the Ronsonol can (butane...the cig. lighter refill stuff you can get at any gas station) Only use a brief puff into the chamber as too much will push out all the oxygen causing it not to fire at all.

For the ignition, I must give myself credit for this one...my idea I have not seen duplicated....I robbed the entire workings of a gas grill starter and rigged the push button on the outside of the chamber, ran the 2 wires running from the button through another 1/16" hole (epoxied shut after feeding the wires) to the sparking mechanism which kinda dangled around on the inside of the chamber. You get the picture....push button...BOOM.

The only problem I found with this design is moisture from combustion of butane. H2O is a byproduct for you non-chemistry types. The vapor had a tendency to coat everything in the chamber sometimes causing a short in the sparker. Solution, open up the poop-chute cleaner-outer and let that baby dry out a bit.

Here's what not to do. (experience) My cousin and I got a bright idea to use an accelerant to further enhance the <i>punch.</i>

Method...fill the chamber with pure Oxygen before introducing butane and igniting. Where did we get pure oxygen? The oxy-acetylene torch in my dad's shop of course!

End result...the spudmaster 3000 came apart at the reducer sending the barrel skyward about 20 feet with a most impressive ball of fire roaring out of the chamber at my cousins face. Fortunately, he had enough presence of mind to have his face slightly turned when doing this....no harm done. But, it could have been another story easily.

But, it's back together now...we don't learn easy...

Good luck!

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merkerguitars

Made them many of times as a young kid in 8th grade....i found what makes good ammo is corn out of the field that is not yet fully grown...i usually shucked it until it fit perfect in the barrel and broke the ear in half...worked just like a bullet...plus i gain some distance....

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fypon

People be VERY VERY careful. Please use a scatter blanket as a minimum or dont do this at all.

My father and I made about 6 versions of potato guns using 2"- 4" PVC. We used every fuel you can imagine from breath spray to right-guard, ether, natural gas, propane, wd-40, etc etc.

DO NOT ever try to use accelerants i.e. pure oxygen. This is a very bad idea.

PVC is brittle and does NOT like to be stressed in by shooting things from them. ABS is a little more forgiving. Besides that the junctions or T sections can be as thin as 1/16th of an inch. I know this because I shattered a 4" T joint that was the base and combustion chamber of exploded. This made about 40 little sharp as hell fragments. One of which cut a 1.5'' gash on my shin to the bone. Cut my shorts in a couple of places. The WORST part was a dull piece hit me right in the head of my johnson! It hurt like hell and bruised it for several days. That’s when I get it all up. My dad continued with his until the next day when the barrel on his reinforced barrel cracked most of the way around.

Be safe with these things, much can go wrong.

-F

theguyondacouch

I have 2. Ones a normal size combustion one powered with butane or ax depending on what i have. I also have a good size pneumatic that is designed to shoot 3/4 inch copper expansion chambers.

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tropple

Hmmm.... I'm think that you could reinforce the chamber area of the system if you set it in a 5 gallon bucket about 5 inches off the bottom and filled it with concrete. Of course you would need to put a metal tube to the combustion hole (?).

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todd

A couple friends and I made one once. All we did was shoot potatoes at walls and up into the air. I didn't think it was very exciting at all. I'd much rather launch a sack of potatoes with my trebuchet.

Sp0rAdiC

hmm... has anyone ever made any type of gun that uses used and/or new 12oz co2 cartridges as ammo?

asudevil83

i made a pretty cool one once, but sadly we used the wrong type of fuel (i think WD40) and fucked up our igniter. but it was a pretty damn fun thing to do.

also, by best friends little brother decided to build his own cannon, but with hollowed out tin cans, duct take, and tennis balls. for a few tries we had a nice flaming tennis ball projectile. but the tin cans eventually got too hot, melting the duct tape, and causing the whole thing to explode. everyone was alright, but it scared the shit out of the neighborhood. people came out from inside their homes just to see what the fuck happened.

tropple

That's what happened to mine ;-)

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Carno

I have made a few with my buddies, and we always built them with a water jacket around the barrel. We used an ignition similar to titty twister's.

Kinda of a pain in the ass to fill the jacket up with water, but we were glad we did the extra work when the whole thing blew up one time.

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TurbineSlut

I want to build a pneumatic version, but still looking around for the right parts. The most problematic being the valve. I have a water rocket installation, which works well and is fun but the pumping to 140 PSI gets very tiring after a couple launches. Gonna get a CO2 bottle as a pressure source soon. A 5kg bottle will get you a lot of pressurised CO2.

For you folks who have made pneumatic versions, did you use a sprinkler valve or something else? I'm thinking a large butterfly valve should do the trick as well. Anyone have any experience with mechanical valves like a butterfly valve? Anyone constructed a homemade diaphragm valve?

I was also wondering how this huge valve works... any ideas?

BoomTruck

You do NOT, repeat NOT want to do that!

PVC or ABS gets brittle when it gets gold. When you turn liquid CO2 (as it is in a bottle) into gas (as it is when it comes out of said bottle), it is extremely cold. That is why regulators will ice up on MIG welders when they are under constant use.

Dumping extremely cold gas into a spudgun and then dumping the pressure again (losing even more temperature) is going to make the entire thing very cold, very fast. Not good.

You want fast air, get a compressor. DO NOT use bottled gases.

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TurbineSlut

Okay, now that is an interesting point. I had realized it was going to get cold, but didn't realize it was going to get so cold that it would affect PVC/ABS that way. Damnit. When I go out to a field I don't have any way to carry a compressor nor the powersupply to power said compressor. I was hoping bottled compressed gas could offer a nice portable solution. But I see now that that maybe isn't such a good idea afterall. Thanks for the heads up.

But I seem to find quite some people on the 'net that suggest CO2 for their spud guns:
* http://www.valuelinx.net/~dthames/carl.htm
* http://www.totse.com/en/bad_ideas/gu.../spudshot.html
* http://www.xinventions.com/main/spud/home.htm

Are these people's guns accidents waiting to happen? Does it really get cold enough for the PVC/ABS to be affected?

I would be using it first on my water rocket installation anyways. The whole thing uses copper tubing and PET bottles. I don't think it could be such a big problem there? I would take all the regular precautions there at any rate: pressure testing the bottle filled with water beforehand, to see at what pressure it fails, and using a long hose to have enough distance between bottle and myself. I haven't actually built the spud gun yet, for lack of suitable parts.

sci

i made a silenced one that shot cranberries in highschool.....it was fun
then we made a much heavier one that was out of pipe i think schedule 40 we used anything combustable on it it shot d cell batteries......far!

titty twister

SCI

I want to hear more about this cranberry gun. Sounds fun.

Do tell...

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Zeld2.0

Hate to bump this up right now but anyone have any recommendations between ABS and PVC pipe? I know PVC pipe is very brittle and very thin and some have mentioned using ABS pipe now but with so many using PVC pipe, i'm just wonderin'.

monkeysugar

When I was making potato guns, we always used abs when available, and sch 80 pvc when it wasn't, only using that for pneumatic guns. I'm not sure how much of a difference it makes, but the ABS we were using was a hell of a lot thicker than the pvc and was rated for higher temperatures and pressures than the pvc. Better safe than sorry, I suppose.

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crazybilly

i have a potato gun and me and some friends wanted to fire it one day but we had no potatos... so what we did is we took a wad of toilet paper and crammed it down in there with a fooseball ball on one end of the wad.. just nestled in there. so i was kind of like one of the old timey cratridges that had wads around the bullet to stabalize it. needless to say the idea worked great and cracked boards on my fence. and shot for a solid 100 yards.. if you use this same idea with a more dense object im sure the results will just be multiplied.. be safe and have fun