A modified ("peaceful") trebuchet.....

[iacob alex]

.....so, not a war throwing simple machine , but a possible gravity powered simple machine ,if we take a look at :
     https://www.real-world-physics-problems.com/trebuchet-physics.html
.....but play a vertical accelerating track ,as Eric Limer's model :
     https://gizmodo.com/9-gifs-that-make-perpetual-motion-machines-a-reality-5994377
     With a simplified leverage (one constant arm-one variable arm) , we can tumble the torque difference on the same side of the fulcrum and...have we a continuous gravity unbalance ("self" motion)?!
     For the modified trebuchet we can play the variable arm ,if we take a look at :
      https://en.m.wikipedia.org/wiki/Perpetual_motion#/media/File%3APerpetuum1png
.....but play a SINGLE ARM !
     The wheel concept is "minimized" as a lever concept...
     Al_ex