So you want to build a potato gun. Well, that's a worthy goal, but you must ask yourself, "What kind of potato gun?" If you're like me, you don't want to make a regular potato gun because that's what everyone else in the neighborhood has. (At least in Idaho) So what do you do? BUILD A SUPPED-UP CANNON OF COURSE!
In this blog, I'll show you how to construct a hybrid potato gun. Generally there are three types of potato guns:
1.) Combustion - Which is what most people make.
2.) Compression - Using compressed air.
3.) Hybrid - Which utilizes both compression and combustion.
More specifically, a hybrid potato gun compresses a fuel/air mixture, which allows more flammable mass to be fit in the chamber which is then ignited. In my design, I pressurize a propane/atmosphere mixture of up to 60 pounds inside the chamber before ignition.
Utilizing this design produces extreme pressures that requires the gun to be constructed of steel rather than plastic. As such, the gun can be very heavy and unwieldy. So, in conjunction with making a hybrid potato gun I decided to make a gun mount modelled after a WWII howitzer cannon - which of course makes the whole thing about twice as cool.
This is about is powerful as it gets with this size of potato gun. The boom is like a thunder and I have only been able to see the projectile in a frame by frame video. It definitely packs a punch, and is quite satisfying to fire.
I found most of the parts for the cannon at a plumbing supply store in town and the rest at Home Depot. Then I pieced together the mount from parts I had laying around my home.
I purposely designed to cannon so that it could be made with no welding experience. Pretty much all the parts are either screwed or epoxied together. The only difficulty that comes with this is that you have to find and fix a lot of leaks before you can operate the cannon, but this is not hard to do.