I was very impressed with the Mechanical Planetarium designed by Zippitybamba and tuned by HackerJack42. There were two things that I thought it needed – a better Saturn and some caps for the screws on the bottom.

I designed a new Saturn, keeping the 18 mm diameter of the planet and then scaling the A and B rings accordingly, and attaching them to the planet at three points. I also preserved the 27° tilt from the original model. I think it looks nice, but be careful as it is fragile.

I used M3 hex socket cap screws. I found that the three screws under the finger wheel could be just about any length that fit. The three screws under the main gear were a different story. Anything longer than an M3x8 would interfere with the main gear. If you find that the main gear hangs up, that could be the problem. Since the design does not provide a countersink for the screws, I decided it would be nice to have caps (that double as feet) for the screws. I designed a quick cap that can be snapped over the protruding screw head. If you need to remove them, just pry them off with a small flat head screw driver.