...to validate the feasibility of your model,can be made with the help os a simple static unbalance test : you must change the support,only.
If you take out from the the bearing / pivot,your model and will fix the central axis on two knife edges ("horizontal lines") ,with the CoG in the upper position,you have an unstable position in gravity.
Set it free...
The CoG begins to fall...
If the result is a swinging motion (to & fro) ,you have not the solution,yet.
If the result is a rolling motion(to,only) ,you have "the key".
All the Bests! / Alex