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

[|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.