Step 1: Build the tube
Note: be sure to wrap it in A LOT OF DUCT TAPE!!!! gorrila tape works better though, and its also a good idea to take the bottom off of vegtable cans and tape to it to add more strength. a good weak point to reinforce is the bottom of the last can. it blows off really easy. i can not emphasise how important this is. if you are thinking, "this is bull, ill do what i want", no. im sorry, but ive tried it and had two launchers explode on me. it is not fun.