Yup old school need and pop fans (steel) made very good tennis ball cannons. Cut the top and bottom off off three of them,duct tape and to end. Fourth can put more holes around the pull tab hole and one on bottom side for lighting hole. Duct tape to other three. Lighter fluid squirt in lighting hole. Shake alittle, insert tennis ball and put lighter to the hol. BAMMMM. Do it right and the ball goes out of sight. Don't think you could do that today. But man was it fun!