Rotating Dice 2

To make one, you'll need:

• 2 small bearings (3x10x4 mm) like these ones:
  https://www.amazon.com/Fishing-Shielded-Miniature-Bearings-VXB/dp/B002BBF59C
• 7 little magnet spheres (3mm):
  https://www.magnetstore.co.uk/neodymium-sphere-magnets/3mm-sphere-magnet/
• a 27.5mm length metal rod, with 3mm in diameter. I think 2.8mm will work.
• two 16mm length screws, 3mm diameter (M3).

Print the parts with 0.1 or 0.2 layer height. I printed the parts with 20% infill, 3 shells. The dice can be printed with 50% to give them some weight and moment of inertia.

Snap the magnets by pressing them against the proper holes (indicated in the image) with a hard surface (a ruler, for example). The magnets holes were made to let the magnets free for spinning, to ensure the attraction force between them (not repulsion). Depending on how the magnets balls were made they can have magnetic poles changing across its surface - or from inside to outside. So, if you get the first type, they will spin and attract each other.

The images show the order of assembly.

The toy makes a nice sound when spinning.

There is a small margin of error, it can stop between numbers, but it doesn't ruin the experience.

Since it has one dice only, it has magnets on just one side, so there are pairs of supports for each version, one with the magnet hole and one without it.

I printed the supports with the drawn faces down. Try reducing the perimeters to one in the first layers. I found that the surface comes out more visually interesting. Just an opinion…

Hope you like it!