I also had this
idea and I think it would be sad, not to make this puzzle. So I'm going to create it with magnets and a metal sphere (thanks Vlad
As far as I know, when such a puzzle is made, the principle is this one : with cylindrical magnet
But I was wondering if it wouldn't work better if the magnets were spheres : with sphere
The magnet would probably not be as strong as with stuck magnet, but there will be less friction because the contact will be between the central sphere and the magnet which can rotate.