Spinner size is limited by hand size. You cannot make it more than 7 bearing large, or you would not be able to spin it. Or could you?
Well, I can spin my 15-bearings spinner:
How did I make it? Old good freeware toolchain works great for me: OpenSCAD + FreeCAD Path
Is it me or is FreeCad 0.19 Path much smarter and much easier to use than 0.18?