A quick catapult design I threw together for a simple "trebuchet" project. Not very elegant, created in Tinkercad. Needs some work, but is designed to use washers as the counterweight for small projectiles. Scaled to incorporate the bearings from: https://www.thingiverse.com/thing:2746804

For anyone doing a similar project:

• Make the frame taller and base larger (more sturdy)
• Make the arm longer (the further out the weight is, the more torque and more power)(the longer of a circumference that the projectile travels, the more inertia it builds up)
• Add a stopper (mine currently stops itself because the weight bottoms out)

I might go on to upgrade this for my own pride, but don't count on it.
Best of luck, fellow nerds