Recently I decided to make a potato gun/launcher. This here page is the 2nd cannon I made.
The first cannon was simply thrown together without any specific dimensions (however, it works great).
After some research I found most of the information reported that a 1.5:1 Chamber to Barrel ratio was
best. So with some help I created 2 calculators to help with creating a potato gun/launcher. Because
PVC comes in specific sizes, the first calculator helps find a good Barrel Length based on your
Chamber Diameter, Chamber Length and Barrel Diameter.
The second calculator finds a good Chamber Length based on your Chamber Diameter, Barrel Diameter and
Barrel Length. Remember to measure the Inside and account for bushings, plugs, caps and even the amount
of pipe slipping into the fitting.
My present potato cannon is designed for tennis balls. It has a 4" Chamber that is essentially 8 1/3"
internal length. The Barrel nets out to 20" the actual cut length is 22" because 2" slips into the
bushing. The Chamber consists of 1 - 4" Female socket adapter and threaded plug, 2 - 4" Couplings
one of which was able to slide right over the 4" pipe increasing the burst strength and finally a
4" X 2.5" insert bushing.