anyone ever made one i knew some guys in high school that made one....they used a spark plug and propane with a valve of some kind not really sure but it would shoot spuds to the moon...lol
I used PVC and a grill starter. its a freakin beast, I'll get you the dimension when i get off work.
I've seen some people use an air compressor and for compressed air into the chamber and launch potatos that way. I'm not sure how it worked tho. Mine used the grill starter and anything flammable that would go in the camber. whatever you do dont use black powder, some kids died in my area using it.
the one i made back in the day, used a 4" pvc "y", reduced to 1 1/2", with a grill starter and hairspray, i shot a stop sign once and dented it, they can be really wicked
yeah mine had the tapered end so the potatoe got cut to size when jammed onto the end, and then use a stick to ramrod it down to the bottom of the barrel