Simple Ball Foot

In many cases it is necessary to equip small pieces of furniture and equipment with additional feet which allow them to be moved easily. In other situations, it is necessary to allow a surface resting on a table to rotate, without altering the objects resting on it.
In all these situations, a series of 3, 4 or 5 ball feet can be useful, which allow easy translation/rotation.
They can also be fixed to the bodies to be moved using screws or a layer of double-sided tape.

My first intention would have been to make the complete foot in parametric design and with the tecnique of the "print en place".

The parametric design of the foot was quite easy in Fusion 360, however the problems arose at the time of printing: making two almost complete spheres in "print en place" did not give the desired results, due to the inevitable "welding points" that are created when printing the profiles of the two endo-contained spheres (hollow sphere and full sphere), and unless exaggeratedly increasi