In my middle school Intro to Robotics class, a group of three 6th grade girls built and programmed a catapult-bot for a game they designed. They used a Touch LED sensor to activate a motor that rotated the catapult arm. The catapult arm design was inspired by the Clawbot arm. They also installed a cross-bar to stop the arm. If they had more time, they would have liked to install motors to control the wheels and incorporated the controller to make the game experience more interactive. At full speed, the catapult was able to hurl a ping pong across a small table. If anybody has ideas for how to hurl the payload a farther distance, I would love to hear your ideas. Looked at these robots but it`s not what I wanted.

You will need to have longer arm and more elastics.

To stop a high speed catapult it is best to use rubber band or rope arrester.

Search forum for “slip gear” to see some of the catapult or puncher examples.


I had a team build a catapult for a game a few years ago… You will need an arm that pushes down on the catapult arm and the pusher arm needs to be a few pitch in front of the center of rotation of the arm. Have it push down on a standoff or something like that. You can make a nice catapult this way. You made me curious and if I get bored I’ll build a prototype tomorrow…

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