We trust that the foregoing has been responsive to your inquiry. If we may be of further assistance please contact us. Jr. Chief, Firearms Technology Branch Building a cannon is a relatively inexpensive hobby. Yet the skill needed is advanced. You need a working knowledge of mechanics, hardware, construction and physics to know what you are doing, and it is good to know simple electronics for the triggers to some guns.
Prices go higher as the diameter and size of the gun increases.
10' 90 deg. Elbow 45 deg. Combustion cannons usually have a large chamber which reduces to a smaller diameter pipe, from which the potato is launched. Combustion is achieved by spraying in a type of propellant, usually hairspray. A flint or electric lantern igniter is used to generate a spark, which ignites the gases, propelling the potato, which can exit the barrel baked.