.....if you simplify the well known "swinging sticks game "(erratic swinging/pendular motion ).
     So , you can :
     -buy one
     -remove (take away,extract) the electric circuit (and battery...) as:
        - https://youtu.be/RlAtXeDY7qs
        - https://youtu.be/PWg6TG2bkFU
     -place a magnet in every stick ( intended to repel one another...)
     - add a "knee joint" (180* limiting rotation joint) for the small stick
    Now , we have the possibility to play a "new game" ( regular rotating inverted pendulum motion ): "self" rotation due to a continuous gravity unbalance on the same side of the fulcrum and rotational inertia !?
    Spare parts : fulcrum/support , two sticks ,two magnets , two joints...if you intend to build and test your own "toy".
     Simply , we replace a battery assisted motion (swinging) with a moment of inertia asssisted motion ( rotation...or "self" rotation due to gravity fall and inertia ).
     Inertia helps every turn ( or half turn...) to tumble the torque difference ( gravity unbalance ) on the same side of the fulcrum ...resulting a continuous pulsatory rotation.


 Al_ex