How to Build a Spud Gun - Videos and Plans to Building a Potato Cannon
What is a Spud Gun
If you grew up on a farm, you are probably familiar with the term spud gun, or its other common name is a potato cannon. Like many pastimes on the farm, some wouldn't consider it completely safe, but it is an impressive display to see a potato launched from a good spud gun. Its one of the great forms of traditional backyard ballistics.
If you've never seen one, they are similar in design to the cannons they use at ball games to shoot t-shirts and the like into the crowds, only cranked up a notch. (By the way, at a recent college football game I attended, an air cannon shaped like a pickle was used to shoot the t-shirts into the crowd!)
Some of these designs create a great explosive sound when fired, satisfying the pyrotechnic urge in many of us. And the range these "guns" can cover is truly impressive.
Building and Testing a Compressed Air Spud Gun
A Compressed Air Potato Cannon
In this video, they build a compressed air gun. It uses lengths of approximately 2 inch pipe as an air reserviour, and what appears to be a lawn sprinkler valve as the trigger mechanism.
They follow the construction up with a sequence of test shots in the neighborhood. You'll note that a compressed air gun is not nearly as loud as some of the other types of guns.
WARNING - Spud guns are not legal in some jurisdictions.
If you decide to build and use one proceed at your own risk, and check with your local authorities first.
There is a listing of places where spud guns have been outlawed at Wikipedia, but this may not be completely up to date.
Books with Spud Gun Plans
Spud Gun Plans
Basically a spud gun is a device constructed with PVC pipes or some similar tubing, that will impel a whole potato that is tightly inserted into the tube. The method of propulsion will vary, some use pneumatics (basically are compressed air), while others (known as combustion launchers) use some combustible gas like hair spray or propane mixed with air. An ignitor like a BBQ starter is used to fire the propane. A few designs are hybrids in nature, compressing a fuel air mixture, which as you may imagine gives an extra pop to the design.
The Backyard Ballistics books gets a lot of good reviews, and it covers a number of projects in addition to potato cannons that appeal to the junior pyrotechnic expert in the family, but are designed to be relatively safe.
There are a variety of places to buy plans and parts for building your own spud gun.
One of the more popular is spudtech.com, but at the time of this writing the owner was selling off the business, so it's uncertain if they are still around.
Make Magazine - Stun Gun Potato Cannon
Build this night lighter potato cannon as a weekend project.
Another Combustion Type Gun
This is actually one of the more complete instructional videos. Ignore the spelling on the instuctions. Do be careful, this is a combustion chamber type gun.
Children's Spud Gun Toys
There are factory made spud guns, which are typically very low power kids toys, which launch small pieces of potato using compressed air. These are available at many toy stores, and are safe for younger kids to play with.
Check the ratings on the individual guns, but you can find some that are rated as OK for kids as young as age 5.