How to Make a Tennis Ball Launcher?

You can make a simple tennis ball launcher with a few cans and some duct tape. Cut the bottom out of one can and 1/2 the bottom out of two cans. Tape the two half cut bottom cans to the uncut bottom can and then tape the full ct bottom can to those cans. Make a small hole in the side of the bottom can for loading the fuel. Put a tennis ball inside the launcher, load the fuel and ignite with a match. You can find more information here: