Steam Powered Potato Pistol 1.0

I thought this up after watching the Mythbusters make a steam powered machine gun. This is a fun little project that lets you shoot potato across the room with a nice pop. It costs about $10 to $15 to make depending on copper prices and parts already in your garage.

A grill lighter is disassembled and used as the heat source for the steam production along with some copper plumbing parts and 1/2" copper pipe. Some water is placed inside the barrel, a potato plug is inserted as an air seal and projectile, and a cork is used as a sudden pressure release. The flame from the lighter heats water to steam and the pressure increases in the barrel until the cork and potato can't hold anymore, then it pops and launches the potato to wherever it's pointed.

This is a prototype steam potato pistol and can be taken a lot further, but I'm just sticking to functioning basics here. Someday I would like to make one with a pressure gauge, quick release valve, and a better handle with the fuel stored inside the handle. I'm calling this version the SPPP1.

It is a little dangerous to build and use because of the flame and hot surfaces, flying objects, and steam; be careful. Playing with fire, pressure, and projectiles is always risky, even on this small scale. Don't shoot an eye out, I'm not liable for any injuries you incur with this. ;( What happened to that "not liable" category of Instructables anyway?

Tools:
Soldering torch
Pipe cuter
Jigsaw
Drill
Pliers

Parts:

• Various short wood screws
• Some leather strips from an old belt to hold the fuel bottle
• Some scrap wood for a handle
• Lead free plumbing solder and flux
• 4" length of 1/2 inch copper pipe

(1) 1/2 inch copper pipe cap
(3) 1/2 inch copper ST 90 degree elbows
(1) bag of copper plumbing pipe brackets
(1) candle/grill lighter
(1) Potato
(1) Cork

Step 1: Start plumbing the boiler and barrel

Cut about 3.5 to 4 inches of 1/2 copper pipe for the barrel. After cutting the pipe make sure to file down the lip on the inside of the pipe formed from the pipe cutter.

Attach the three elbows together at the end of the barrel to form a curl and put a cap on the last elbow.

Dry fit all the parts as shown in the photo. Make the elbows form off to the side so a flame can heat water inside the cap.

Comments

[NE patsrock]

hey where did you get all that coppor

[Philisawesome]

I built one with the pipes out of my neighbors crawl space. Just kidding. But If you want to find copper pipes check Home Depot or Lowes, or what ever home improvement store you like best.

[mase2150]

really cool i am making 1 2

[nilved]

did u make it up?

[nilved]

dude this is amazing im blown away :O
steam punk is awesome

[|3AZ1L]

hey, i was just wondering what the reason for the barrel bend being over the top like that is? does it serve a proper purpose or would you be able to achieve the same thing with just a 90 degree downwards bend? thanks

[robbtoberfest]

Both for looks and some function; but I think your idea would work too.

[dfuller1]

Nice Instructible! I love this kind of project and may have to try this with my son.
One tip for sweat soldering: (I certainly don't do this every day, but several times a year for the last 20 years or so). I finally gave up on using the tiny brushes for the flux and just use my finger to spread it onto the joint before soldering. I seem to get a lot more consistent results that way.

[matwyatt]

one follow up to that would also be instead of soldering or perhaps as well as using some form of epoxy putty or perhaps 'gungum' the exhaust putty' that should hold up under extreme temps =]

[matwyatt]

Hey nice ible but wouldn't it be easier although more gas consuming to use one of the jet type lighters that way you would also negate the wind effects if your outside and make ur steam much faster just a thought =]

[wiggins8472]

I have made an instructable defining how to make the device with a "Zippo(tm)" brand lighter as the heat source. What do you think? I would love to hear your thoughts.

http://www.instructables.com/id/Steam-Powered-Potato-Pistol-Zippo-Mod/

[robbtoberfest]

That is AWESOME! Thanks for the credit.

[wiggins8472]

Thank you! I really appreciate your comment.

[blinkyblinky]

You could use hairspray or perfume instead of steam to launch your cork and potato cutout by using the igniter to ignite it.

[Sowee]

But, there are a lot of ibles like that! This one is unique, dont you think?

[blinkyblinky]

But it takes forever, right...you even had to time lapse! If this were a weapon for on the go, then it would not be practical because it wouldn't launch int time.

[nanosec12]

I think the basic point you need to realize here is that it is not intended as a 'weapon' just an interesting experiment.

[germanfist]

its the novelty of it. its not necessarily cool because you can shoot it fast or in a practical manner. Its a STEAM powered gun, not just a pile of copper and solder to be filled with whatever fuel.

[mitch and sean]

This is fanTASTICAL

[Sowee]

Very nice project, my friend!

[ilpug]

I admit, i have been lazy. Ive been on the site for years, and have seen this project a bunch, but i never got around to clicking on it. now that i have, i am amazed. this is very original, and a great build. it could use a slightly more visually appealing design, but this is a great proof-of-concept. I might make one of thee, but with an on-demand system like a ball valve.

[tictaclad]

 i love the idea but i think it takes to long to fire. and while your making it why not make a normal potato cannon?

[Father Christmas]

A torch lighter might decrease fire time by a bit.

[sharlston]

normal potato cannons are lame and arent portable

[bowmaster]

But you can take out cars with them. And a small (~4 feet) potato cannon is very easy to carry.

[sharlston]

but thats under 4 foot what about the really long ones

[zack247]

whats easier to carry is a mini potato cannon, at 1 foot.
even those small things can pack quite the punch.

[bowmaster]

In terms of weight, up to +10 feet isn't that heavy. It's just the length that gets in the way.

[ilpug]

you could always make one that breaks down into sections

[javajunkie1976]

This. Is. So. Freakin. Awesome!!! I love it.

[Kinnishian]

 Have you considered updating it with blue flame butane burners? They're very hot, but placed correctly shouldnt melt the copper. 

[snowluck2345]

they wouldn't melt the copper. How would you place them wrongly to get them to melt copper?

[Kinnishian]

Ok, I guess they will never melt the copper. But they can get thinner copper soft enough to damage things (E.G, you can melt the thin shell of a penny enough for it to collapse under the molten zinc, I don't know enough to know when a copper is thick enough that it doesn't matter how much butane flame is touching it.

[snowluck2345]

It wouldn't damage the copper, howevver it could melt the solder which could let the built up steam escape, unless the steam absorbed the heat.

[robbtoberfest]

Yes, that's a great idea. I'm still pondering different styles. Maybe even a large Fresnel lens mounted on top to make it solar powered. ;)

[LiquidLightning]

Have a bit of nichrome wire inside the boiling chamber with the ends stick out through holes connected to a 9v battery and a switch. Or a mechanical pencil lead.

[bhumphreys]

awsome

[eurofyter966]

Sir, I challenge you to a duel! Steampunk is awesome, as is this pistol. What if instead you just had a straight pipe with the heater at one end and above it a valve with a small pipe attached as a water container (the water container would be sealed). Then when the barrel is hot enough to instantly vaporise water you would open the valve and let the water hit the hot surface of the barrel instantly turning it into steam and launching the potato. That way you can control when you fire it. But anyways great instructable.

[Celt]

This method could be used to launch bottle rockets strait up! Pretty cool.  I think some people missed the point of the build..... "Why build it"  you ask?  Because I can.  Thats why.  Thats what hacking gadgets, experimenting, inventing and tinkering is all about. well done.

[tjmortenson]

 I just bought the parts to build one with a pressure gauge and a ball valve.  I'll post pics when I finish it.

[robbtoberfest]

 That sounds cool, I can't wait to see it. I've been busy building onto my house this year, so I haven't had time to do fun projects like this in a while.

[77Kapn Krunch77]

why dont u just shoot corks?

[temp]

cause then it wouldn't shoot potater bits.  :)

[lucek]

I remember when mythbusters did a steam cannon a few years back. episode 55 "Did Archimedes make a cannon using steam power?"
nice super small scale however.

[Metalcaster14]

good 'ible well presented I might have t try this sometime

[mikaelthemycologist]

Now that's steampunk

[irlolcopter]

you should take a peice of pipe and try to extrude the end to make it wider/ flared. use this to cut your potato "corks". without needing an actual cork

[Stephen D. Alverez]

I thought this was going to be another "just for show projects", but then i watched the movie and it blasted the coke can! this thing is the coolest!!

[XkidXhavocX]

tie a string around the cork so it doesnt get destroyed when it is sandwitched between the potato and whatever your shooting att..... and also so you dont have to go find it every time you use the gun

[nutsandbolts_64]

Maybe a homemade electric heating element to turn up the heat, and pressure.

[zoologistnerd24]

this is awesome

[Blacklight]

oh my gosh, this is so cool. I'm not really into poptato guns, but it's cool that it works, and my friend would lol at this.

[shakeel106]

it would be awsom if you were able to bring that so school

[qwerty29]

i feel stupid but what exactly is steampunk?

[lordhazzard]

As jake von slatt says:
Steampunk is Goth, Punk, Geek, and Maker Culture whipped into a delicious melange with a healthy seasoning of political and environmental activism. It's the intersection of science and romance, it's sustainable rebellion.

[standacrazytaco]

the way i see it its like the future in the past if that helps

[robbtoberfest]

My easiest way of explaining it to people is to watch the movie Wild Wild West with Will Smith. The cool tech style in that movie is a great example of steampunk but is not limited to just that.

[nutsandbolts_64]

Menn I love that movie, real funny, that last part where u tink its a horse they're riding on when its that giant 80 foot mekanikal spider, gatling gun and incendiary cannon included LOL:P

[qwerty29]

thanks

[flamethrower1010]

hey try putting a string through the cork and securing it to the barrel or something so the cork would be jerked down and out of the way of the potato so it is the only projectile flying. It would probly make the potato have a lot straighter flight if you shoot from a longer distance. great ible too

[templar627]

wow thats really cool; and its one of the cheapest potato guns around to fire it's like just add water. only bad thing is that it takes a while to warm up

[larze]

Pretty interesting. This reminds me of a potato gun which is actually in a local village museum in a distant rural area. There was a handy blacksmith in the village and after him there are lots of interesting stuff left. Like speaking about wind generators and a muzzle loaded guns etc, all self made and now in display in the museum. The potato gun is one of the items. The current museum caretaker cannot explain how the gun has worked, but maybe it's this way. Deciding from what this instructable tells and what I remember about the gun, it might be that instead of the cork, there has been a lever holding the potato in the pipe, then pushing the lever the potato has released. Interesting! The gun might be almost 100 years old... from the times of my great-great-grandfather.

[robbtoberfest]

That sounds cool! Can you post a pic or two?

[luke]

very nice work ! it has given me ideas .... im thinking camera flash circuits to vaporize the water faster than a flame could boil it ?

[GEAR]

Steam power, well done, the word steampunk is new to me but the concept is not and from what I see this is a very good example of it. Thanks for putting in the effort to make the insturctable.

[Mattrox]

very cool if you want it refillabile this would be good

http://www.trademe.co.nz/Browse/Listing.aspx?id=196911660

[Arbitror]

Awesome job! This is toatally STEAMPUNK! It looks steampunk, and it works on steam! 5 stars!

[Kaelessin]

just another thought(your project certainly is thought provoking!): do you think a wider bottom on the boiler would make for faster steam production?

[robbtoberfest]

I think so, the water would have more surface area on the hot part.

[robbtoberfest]

Thanks for all the great comments; I hope to start on the improved version soon. Adding a safety valve, pressure release trigger, a gauge, and checking pressure ratings of the components are on my list. A refillable fuel container would be nice too; I don't want to take a new lighter apart every time I need fuel.

[sadunpererarules]

arent all BBQ grill lighters refillable?

[robbtoberfest]

Not this one I used, it was a dollar special.

[Kaelessin]

heheh i love those dollar specials! It'd increase the scope of the project a fair amount but what about a custom burner . . . if you could pull off a butane fueld one youd have that marvelous blue flame too!

[carpespasm]

A few questions I thought of while reading: Where did you get the measurement of water? Does anyone know the pressure rating on copper? Did you avoid using a valve to prevent a boiler explosion? Maybe a water-heater pressure releif valve would be beneficial in a later version? I really like the idea of using the grill lighter for a flame source. I might make one based on yours with a pressure gauge, valve, and some shielding around the flame to keep it more reliably lit outdoors. I'll have to wait 'til I get some play money saved though I think.

[thebluemartyr]

Copper can hold several hundred PSI, which means that this is completely safe, and not a chance in hell this will ever generate enough pressure to put any strain on it.

[robbtoberfest]

I guesstimated the water amount, I haven't played with different amounts. I'm going to try less water yet for possibly faster steam production and shots.
I haven't calculated the pressure rating, but I will soon for the next one. This site has some cool info on bursting pressure: http://www.engineeringtoolbox.com/pipes-pressure-rating-t_40.html
I assume the cork should blow before the copper.
Definitely the next one will need safety features such as that water-heater pressure relief valve...good idea.

[carpespasm]

As long as there isn't too much water in it I would imagine the solder joint would have to melt before a setup with a valve would blow. I don't think with just a stopper you could plug this sort of gun enough to blow. If you wanted to really go all out making the next one from black iron with one of those jet style lighters to heat in a more rifle shaped form would be the most out there shape I could see this project taking. I might just draw up a plan for such a thing.

[carpespasm]

Excuse the crude diagram, but this seems like it would be a nice set of refinements to your idea. It should be safe and more informative as well. You don't have to turn around to load the water where it needs to be as well. Brass ball valves are pretty cheap and should hold up to the heat pretty well too.

[wiggins8472]

I had a thought while at Home Depot looking through their brass valves and such. Would the pressure gauge really be necessary if you had the safety release valve? You would just always know the chamber pressure was less than the pressure of the valve unless steam was coming out of it.

[carpespasm]

it wouldn't be needed for safety, but it might be nice to have so you know when it's ready to fire off or for experimentation uses.

[wiggins8472]

I think this diagram is pretty neat. However, with more volume in the chamber pre-valve I think you would need more water and more heat to get up to pressure.

[thebluemartyr]

His design is already quite safe, copper is more than capable of holding the pressure, all he needs really is 2 ball valves, one for water input, and another for steam release. Pressure gauges would not really be needed, you could probably just time it instead of monitoring the pressure.

[carpespasm]

All good to know. I guess the pressure gauge would be more for scientific purposes and the steampunk look.

[robbtoberfest]

Very nice!!! I'll definitely use some of this idea. Just need a trigger release for perfection.

[robbtoberfest]

Awesome! You could build that one and we could start a steam gun group.

[robbtoberfest]

If steam whistle valves weren't so expensive that would be the way to go for the trigger. I'll have to find a deal somewhere.

[KEYBOARDISBROKEN]

a metal kettle with a sticky-out spout should work as a boiler -weld/solder the top shut and weld/solder the gun barrel to the spout

[blugyblug]

Oooh nicee... But 25-35 feet isnt too much, especially for a 1-2 minute waiting time. But this thing looks rad. Id prefer making a capacitor bank and boiling the water with electricity (Shove some electricity through the boiler? Then coat it with something to stop yourself getting shocked.) It would probably shoot faster and stronger... Yeah im only 13 yrs old, shouldnt be making things like this lol.

[KEYBOARDISBROKEN]

erm... try rigging it up to an electric kettle

[Kryptonite]

Heating water with electricity is probably a really bad idea, no offence, I'm 13 too. Possibly a heating element and instead of the cork, maybe a butterfly valve/ball valve?

[blugyblug]

But then you might as well make a spud gun -.-

[blugyblug]

It really depends on how you do it. In the end it wouldnt really be a pistol anymore, more like a cannon 0.0

[Kryptonite]

I think this is not really a "useful" item, more like a novelty for some body who like to make. I think i'd like one of these better than a normal spud gun.

[robbtoberfest]

Right on my friend, that's the whole point of this toy. Maybe the next one will be a little less cumbersome and a little more effective.

[Kryptonite]

Looking forward to it, thanks for posting!

[Kryptonite]

Wow, that is definitely epic. I love the originality + and ultimation steampunk-goodness all adds up to = 5 stars and favourited!

Although, for the next one, a valve of some sort for safety, a pressure gauge and some way to have controlled shooting instead of waiting for the cork to pop. Up to you, I trust you shall amaze us all again for SPPP2!

[maxpower49]

did the potato dent the can or the cork

[robbtoberfest]

It's hard to say, I slowed the video down and they both hit about the same time. The cork bounces back toward the door while the potato continues forward.

[PKTraceur]

That is so Steampunk... like, literally!

[bob the builder #1]

Nice! about taking it further I would add a safety pop off valve and a ball valve to shoot it.

[matfam]

Looks cool. A couple of thoughts though. That copper looks like type "M" or standard water pipe copper. I would use type "L" or refrigeration copper (thicker walls). I would also braze everything together, its stronger and melts at much higher temps. Great Job

[sssssbooom]

type L would take longer to heat up

[IW5 Industries]

that is so steampunk!!!!!!

[lordofthedonuts]

I guess if you use a small butane torch instead of a BBQ lighter the pressure would build faster, the solder would needs to be made of silver, though. Awesome!

[maxpower49]

this is sweet you should put a string on the cork so when you think it is ready you can pull the string to remove the cork and shoot the potato

[KentsOkay]

One word: STEAMPUNKGOODNESS!! 5 star, and fave!! I look forward to a more controlled version..

[LinuxH4x0r]

Sweet!

[Kaelessin]

Brilliant!!! the guage would certainly make it look cooler . . . true steampunk

[Login258]

This is awesome. I love it.