Potato canons have always fascinated me, all the old cool kids had em when I was young... But everytime I went to look for plans they were too expensive or complicated to build. So I said screw that, and built my own. Oh, and it only cost me $25. Woot!

 

Disclaimer! This is dangerous. In fact, it's probably illigal too! Don't do it. I didn't.

 

1. Materials

  • 3' section of 2" ABS pipe, $5
  • 2" threaded coupler, $1
  • 2" threaded end cap, $1
  • BBQ sparker, $13 (sold as a replacement item)
  • ABS solvent glue, $5
  • Couple of #8 or #10 machine screws and matching nuts. 
  • Hair spray. 

 

2. Contruction

 Clean off one end of the 3' section of ABS and the coupler and remove any really big plastic burrs. Let them completely dry, then really quickly apply the ABS solvent to both the inside of the coupler and the outside of the pipe. Jam them together and dont move them for 15 minutes. Once the two are glued, assuming you did a good job, they will never come apart.

 

 

 

Drill two holes just big enough for your machine screws at a 90 degree angle to each other about 3" from the end. Drive them in and  put a nut on the inside so they dont blow out and take out an eye when you fire the gun. If you used long screws, then put 2 nuts on the outside of the gun as well to connect the BBQ sparker.

 

Take your BBQ sparker and strip the ends off the 2 wires. Sandwich them between 2 nuts on the machine screws that are driven into the potato gun. 

 

 

Move the screws apart so that they make a 1/4" gap inside the gun. Blow all the air out of the gun (using your lungs) since the glue fumes are flammable and then try the sparker. You should see a little spark fly across the gap between the 2 machine screws. If not, move them closer together, check your wiring and try again. Grab some heat shrink tubing or electrical tape and cover up any exposed metal so you dont shock yourself.

 



 

Last step, grab a rasp or a file and taper the muzzle end of the gun so that when you jam a potato in, it will cut it down to the perfect size.


3. Wait! No seriously, wait.

The last thing you want is the end of your gun blowing off, ABS shards flying everywhere and somebody losing an eye. Wait a good 12 hours or so for the glue to dry before firing it. You should probably have something that looks like this...

 



4. Fire!

Test your propellant of choice (I used hair spray) by lighting a piece of paper on fire, and spraying it with the can. If you get a nice whoosh of flame, you're good to go. Don't use spray paint! It will cover the machine screws and you won't get a spark. Jam a potato down the barrel about half way, unscrew the end cap and put a 1 second burst of spray in the gun. Wait for 20 seconds, stand back and click the ignitor. If all goes well, giggle like a little girl and feel badass as you know have a working potato gun.

 

 Big list of propellants to try: http://www.aaroncake.net/spuds/boom.asp

 


Video of it in action

It's probably a good idea to secure the gun as well... As you can see the recoil is quite strong in the vid. The sound got messed up too and you can't hear the nice BANG as it goes off.

 

If your gun doesn't work, open the end, remove the potato and air it out then make sure the sparker works. It will take a few tries to get the right mix of propellant/air so play around with it. If you put too much in, there's no oxygen and it won't ignite. Not enough and the potato won't make it out of the barrel.

 

Enjoy your new toy!