Potato gun facts for kids

A typical factory-made toy die-cast spud gun. The cap attached to the muzzle converts it into a water pistol.

A potato gun or potato cannon is a device that shoots objects, often potatoes! It works by using either a small explosion (called combustion) or strong air pressure to launch a projectile. People call them potato guns because potatoes are a common and easy thing to shoot from them.

There are two main kinds of potato guns. One type uses a burning fuel and a spark to make an object move. The other type uses air that has been squeezed very tightly. Potato guns are usually built from plastic pipes, like those made of PVC or ABS.

How Do Combustion Potato Guns Work?

Parts of a Combustion Potato Gun

Combustion potato guns have four main parts:

• Barrel: This is the tube the projectile shoots out of. It's usually narrower than the part where the fuel goes.
• Combustion Chamber: This is where the fuel is put. The igniter is also located inside this chamber.
• Igniter: This device creates a spark to set the fuel on fire. It's like a trigger. People often use electric grill igniters or special lighters.
• Cap: This part connects to the combustion chamber. You take it off to add fuel and put it back on before firing the gun.

Firing a Combustion Potato Gun

Here's how a combustion potato gun works:

1. First, the person using the gun puts a projectile into the barrel. A long stick, called a ramrod, is often used to push it all the way down. The projectile must fit very tightly in the barrel. This makes sure the pressure from the burning fuel is strong enough to push it out. This is why potatoes are often used, as they can be cut to fit perfectly.
2. Next, the cap is removed, and a flammable fuel is sprayed into the combustion chamber. Hair spray is a popular choice because it catches fire easily. Once the fuel is in, the cap is put back on tightly.
3. Finally, the cannon is pointed at its target, and the igniter is pressed. This causes the fuel to burn very quickly. The fast-expanding gases push the projectile out of the barrel at high speed.

A potato cannon can shoot a 2-inch wide potato over 100 yards (about the length of a football field) at speeds of 40 miles per hour. This shows why potato guns can be dangerous if not handled with extreme care.

How Do Air Powered Potato Guns Work?

Parts of an Air Powered Potato Gun

Air powered potato guns also have important parts:

• Source of Compressed Air: This is usually an air compressor that squeezes air.
• Barrel: Just like with combustion guns, this is the tube the projectile shoots from.
• Air Reservoir: This is a tank where the squeezed air is stored before it's released. It does a similar job to the combustion chamber in the other type of gun.
• Release Valve: This is a special valve placed between the air reservoir and the barrel. It acts like a trigger, letting the air out quickly.

Firing an Air Powered Potato Gun

Here's how an air powered potato gun works:

1. First, the person puts a projectile into the barrel. A ramrod is used to push it down firmly. The projectile needs to fit tightly so the air pressure can push it out strongly.
2. Next, the air reservoir is filled with compressed air from an air compressor. The release valve must be closed during this step.
3. Finally, the cannon is aimed, and the release valve is opened. This causes the squeezed air to rush into the barrel very quickly. The high pressure forces the projectile out of the barrel.

Air powered potato cannons are much more powerful than combustion cannons. A combustion potato gun usually launches projectiles with about 10-20 pounds per square inch (psi) of pressure. Air powered guns often use pressures over 100 psi, making them very strong.

Images for kids

• 

  A pneumatic potato cannon.

• 

  A PVC dry ice cannon in use.

• 

  A typical propane gun bird scarer.