This video demonstrates how to use homemade handheld cannon. For this project, you will need the following: an ink pen, duct tape, and air soft BB. Use a ballpoint pen to make the cannon, using rubber bands as the mechanism for propulsion. This should be made in advance. Once your cannon is complete, you can use your cannon to propel the dowel that you've made from the inside of the pen. For that, you should have duct taped one end of it. You can also use it to shoot air soft BBs as cannons. Place your homemade cannon ball inside the cannon and propel it with the rubber bands. If you like, you can even make a target board to aim at.