How to Make a tabletop catapult (aka a Mangonel)
This is a great little catapult that uses torsion from twisted rope or string. It is more accurate to the types of catapults used in the middle ages because they didn't have rubber bands back then but they did have rope. The rope can generate enormous force that is used to hurl a projectile.
This type of catapult is more specifically called a Mangonel.