Cat exercise wheel

This is a cat (pet) training wheel, which is my most complex work to date.
Due to the complexity of the design, only one of the repeating elements is included in the design, except for the tread.
Each element is downloadable, with the name indicating how many pieces are needed.
The elements can be fixed together with M5 screws, the same size is needed to fix the wheel.
The support rods and the elements must be assembled by gluing.