How to make a catapult

Hello can anyone explain how to make a catapult? I want to use it for my shooter for the ball.

This thread may point you in the right direction:

https://vexforum.com/t/8059a-and-d-singvex-reveal/48676/1

You’l probably want to take note of the slip gear and ratchet components in the catapult - they are quite important.