Variabile arm...

[iacob alex]

.....as a particular design , intended to play a continuous gravity unbalance , at :
     https://m.youtube.com/watch?v=jOeUBGUI3rIh
     You can play this concept...as you like...
     Al_ex

[iacob alex]

.....or more precisely an oscillatory variance of a single arm of a lever , as :
     https://m.youtube.com/watch?v=CJnSeTmMau4
...can be a suggestion to replace the circus performance(the to and fro translation of the center of mass , so to play a rotating seesaw) , with  "something" equivalent.
      Al_ex