Firecracker Cannon

	A long time ago I did a project to make a firecracker cannon. The point of that project was that I could get all the parts at a home supply store. However, there were some things I did not like about that cannon. Specifically, it was a real pain to reload because you had to unscrew the endcap to reload. Also, the threads of the endcap would get fouled with residue from the firecrackers. The plywood pieces are all cut from 2.7 mm plywood and were all cut on my laser cutter.
	This cannon breaks open, hinging on the axle. You put the firecracker in with the fuse sticking out. When you close the barrel back down, the fuse is left sticking up, perfect for lighting! As with the older firecracker cannon, you can insert another firecracker fuse-first in the barrel to serve as a projectile. The explosion from the first firecracker lights the fuse of the second firecracker and sends it across the yard. It is so much fun.
	After about 10 firings, this happened. It is a design flaw.
	Here you see a couple of incremental improvements. The first one was to make the beam taller at the point where the endcap attachs. The second is to add an additional ply on both sides of the beam. This design has worked through many, many firings.