This is a scale model of the test rig. I tried to keep it as faithful as possible to the original while making it reasonably printable.

Printing

Nothing special here. The model is scaled to about 60mm tall. You can scale it up or down as needed. There's a bit of overhang, but you probably don't need support material.

For the print shown, I inserted 2 color changes on the “bottom” model so that the base was white, the hemisphere was silver and the core was glow-in-the-dark.