My first fully operational trebuchet design. Inexpensive, lightweighted, all made from wood. Very efficient with tennis balls, waterbombs, or (boiled) eggs..
https://en.opensuse.org/images/2/20/Trebuchet_simulation_slides.pdf
https://www.thingiverse.com/thing:3761789
https://www.youtube.com/watch?v=IiG2VPLTDpg
https://www.youtube.com/watch?v=-Pv-yPBlofo
https://www.youtube.com/watch?v=MHek-5BepOQ
https://www.youtube.com/watch?v=J0sa-UWGPxY