Made a potato cannon, called it Spudnik. Had lots of fun with it 
Basic plans:
What I did was take a 3ft piece of plumber's piping approx. 3" across in diameter, or so. Call it the barrel. Then I took a T-shaped joint...call it the combustion chamber. I cemented the combustion chamber to the barrel by one arm of the "T", so that the bottom tip and the other arm of the "T" were free.
I got 2 screw-in caps for the open ends of the combustion chamber. I drilled a hole in one cap and installed a brass flint striker so that the flint is, obviously, inside the combustion chamber. Finally, I taped up all the joints and whatever with duct tape, just in case. Now, when I put the remaining cap on the bottom of the cannon, there is only one way the spud can go, and that's out through the barrel.
Ammunition were selected big, white potatos. I put the potato over the muzzle and whacked it in with a large rock. The pipe will cut the potato to shape. Then I used a stick to push the spud down to the bottom, but not INTO the combustion chamber.
Next, I invert the cannon, unscrew the bottom cap and spray hairspray into the combustion chamber. Do not shake the hairspray...you only want the flammable gas in there, not the hairspray liquid. I cap the chamber and screw the cap in quickly, then I brace the cannon on the ground, aim it somewhere safe and twist the igniter. Potatos can fly very far if you give them half a chance, heh.
Basic plans:
What I did was take a 3ft piece of plumber's piping approx. 3" across in diameter, or so. Call it the barrel. Then I took a T-shaped joint...call it the combustion chamber. I cemented the combustion chamber to the barrel by one arm of the "T", so that the bottom tip and the other arm of the "T" were free.
I got 2 screw-in caps for the open ends of the combustion chamber. I drilled a hole in one cap and installed a brass flint striker so that the flint is, obviously, inside the combustion chamber. Finally, I taped up all the joints and whatever with duct tape, just in case. Now, when I put the remaining cap on the bottom of the cannon, there is only one way the spud can go, and that's out through the barrel.
Ammunition were selected big, white potatos. I put the potato over the muzzle and whacked it in with a large rock. The pipe will cut the potato to shape. Then I used a stick to push the spud down to the bottom, but not INTO the combustion chamber.
Next, I invert the cannon, unscrew the bottom cap and spray hairspray into the combustion chamber. Do not shake the hairspray...you only want the flammable gas in there, not the hairspray liquid. I cap the chamber and screw the cap in quickly, then I brace the cannon on the ground, aim it somewhere safe and twist the igniter. Potatos can fly very far if you give them half a chance, heh.
