I designed a simple and fun little device myself. Installation instructions are shown in picture.It 's very easy. I hope you like it.

Special Instructions:

The diameter of the ball must not exceed 20 mm. Print directly from the downloaded file.

(Pay attention to model contact surface with hot bed when printing)

Recommended using a lower layer hight (0.15/0.2mm) for better results in details.the colors are up to you，This model was printed using PLA.

enjoy it!