I made this trebuchet for fun a while back and thought I'd share it here :)
I did not make the 3D model (I found it for free online a while back and unfortunately can't remember the artist's name).
It is HUGE (20m tall) and would definitely collapse under its own weight.
What you need now is a giant pumpkin and some target markers, and we can have an accuracy contest going!
I like how the cable is whipped around by the movement of the throwing arm (all emergent behavior, of course).