My project was to create a turtle where the head could be pivoted around kind of like a joystick. These are some of the different views of the CAD file. The spheres that are supposed to be its feet don’t pivot. They are just embedded inside the body.

 

This is an isolated view of just the head. The sphere on the left side of the picture would be contained in a cavity in the body/shell, and the hole would small enough so that the head piece can’t be removed.

 

EDIT:

So my 3D printed turtle came out, but it doesn’t work. The head component doesn’t rotate like it’s supposed to, so I will probably reprint it with a larger gap between the inside head sphere and the rest of the body.