What is it ? a machine used to throw heavy payloads at enemies. It was used in the middle ages.
How does it work ? It works by using a counterweight, when the weight falls it uses that energy to launch something (ex. A rock or a ball) at high speeds. The counterweight must be heavier than what you are launching to get the maximum speed.
What was it used for ? It was used in battle to throw far distances. It was more accurate than the catapult.
Purchase the Keva Set here or build one of your own.