The Original Potato Cannon

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Introduction: The Original Potato Cannon

About: I liked designing and building things long before I became an engineer, now I get paid to do it!

In this instructable I'm going to teach you how to build the original hairspray powered potato cannon. Sometims it is also called a potato gun. Making this cannon takes about an hour and $30. The finished gun can shoot potatoes over 100 yards!!!


Step 1: The Materials

Building Materials
-5 feet of 1.5" ABS (DWV) pipe
-2 feet of 3" ABS pipe
-A 3" to 1.5" reducer
-A 3" threaded adapter
-A 3" end cap
-A BBQ ignitor (+1 Screw)
-ABS cement

Consumables
-Cheap aerosol hairspray
-Potatoes or similar legumes

Tools
-Hacksaw
-Drill

Step 2: Assembly

-Cut the 3" pipe to about 13" or a size you prefer (the larger the combustion chamber; the more gas; the more boom)
-Make sure the reducer fits over the pipe
-Spread some ABS cement on the inside of the reducer and outside of one end of the pipe, slide the reducer onto the pipe with a twisting method
-Repeat this for the threaded adapter
-Repeat this for the barrel (5' of 1.5" pipe)

Make sure your gluing is done properly, you dont want it to explode.

Step 3: Install the Ignitor

You probably saw in the last step a silver BBQ lighter attached to the side of the pipe, I tried using this, but it wasnt working, so I bought an $8 ignitor.

Drill a hole in the 3" pipe for the metal lead from the ignitor to fit, mount the ignitor using screws provided, you can slop some glue around the hole to make sure there wont be a gap where the flames will shoot out and burn your arm......

In order to create the arc (spark) to ignite the gas, there needs to be a metal contact between the lead from the ignitor and the metal chasis of the ignitor.

If you mounted the ignitor with bolts into the pipe, bend the metal lead to be within 1/4" of the bolt to make a spark,
I however put another screw in from the other side, but had to run a piece of wire from it to the metal chasis.
Both methods will work.

Step 4: You Are Finished; Firing

Let the cement cure for a couple hours.

Firing:
-Unscrew the end cap
-Force a potato into the barrel (this is easier if you sharpen the end of the barrel with a file)
-Pack it down with a broom, make sure its still inside the barrel, and not the combustion chamber
-Spray some hair spray into the 3" pipe for 2-3seconds
-Quickly screw the end cap back on
-Point it at a 45 degree angle to maximize range and push the ignitor

11 People Made This Project!

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537 Comments

0
BrettS34
BrettS34

Tip 7 months ago

I would strongly recommend using schedule 40 pvc as opposed to abs and I would NEVER recommend firing one of these against your cheek looking down the barrel. These CAN fail. If you plug that barrel too hard or use too much accelerant that chamber could explode. These ar not toys. They used to be classified as homemade firearms in the 90's.

0
BrettS34
BrettS34

Tip 7 months ago on Step 3

I've been making these for almost 30 years. What I do is take the button portion of the bbq grill ignitor and cut a piece of wire coat hanger a couple of inches long. Put a 90 degree bend at the last 1/4 inch of it. On one side of the ignitor is a small metal wire that is the ground. After cutting and bending the coat hanger wire take a file or burr and abrade it exposing the shiny metal. Glue it with epoxy to the side of the ignitor up against the ground wire with the bent end about 2-3 mm from the tip. You can use electrical tape but it will eventually burn up and fail. Essentially you're making a spark plug. Many of the ignitors today have a jam nut you can thread on but instead I slip a speed nut up after putting it in the hole you drill. Then after you have it snug apply a liberal amount of epoxy around the button and let it set for a day or so. The ignitor is the weakest point with these contraptions so you want to make sure it is secure and doesn't blow your thumb off! Also we always used WD-40 instead of hairspray. Hairspray is highly flammable but it it will gum up your ignitor after a few uses. Happy shooting!

0
1liular
1liular

6 years ago on Introduction

Can you cut the 1.5" pipe to 3 feet ,instead of 5?

0
BrettS34
BrettS34

Reply 7 months ago

You can. I made one once and it still fires but with about 1/2 the combustion and range

0
Teh32Chicken
Teh32Chicken

Reply 2 years ago

I think so, you'll just get less range

0
yarnahoop
yarnahoop

Reply 4 years ago

i think it will still fire fine but the potato probobly just wont go so far

0
FlorinJ
FlorinJ

Reply 4 years ago

Sure you can. It will reduce the range, though.

0
AlbertoB15
AlbertoB15

6 years ago

I've made one, except I did go with steel pipes, silicone, rivets, and duct tape, and I'm using starter fluid as a propellant. Packs a hell of a punch.

0
I Am Here
I Am Here

Reply 8 months ago

After you shoot it, is it hard to get the cap off so you can add the fuel?

0
Charleshall2
Charleshall2

Question 1 year ago on Introduction

I built my potato gun after watching your video it worked great once I cannot remove the rear cap after firing I cut off the existing one and pvc'd a new fitting and a new screw cap on fire it again and the end cap won't come off

0
I Am Here
I Am Here

Answer 8 months ago

Did you ever figure it out?

0
steampunkpotato
steampunkpotato

Reply 8 years ago

the simplicity of that burn was lovely

0
201129120
201129120

2 years ago

me and my frend are doing this for our sience project

0
RaduR6
RaduR6

Reply 4 years ago

Drill some holes through the sides of the cap and the end of the combustion chamber so you can stick some nails through. Or just use a ton of epoxy to seal the cap and mount a bottle cap somewhere on the combustion chamber with another ton of epoxy for fast and easy loading, like I did.

0
201129120
201129120

Reply 2 years ago

hi frankie