Rotating Dice

This was totally based on these nice and well machined rotating dice:

To make one, you'll need: - 4 small bearings (3x10x4 mm) lke these ones: https://www.amazon.com/Fishing-Shielded-Miniature-Bearings-VXB/dp/B002BBF59C (Not sponsorship) - 14 little magnet spheres (3mm): https://www.magnetstore.co.uk/neodymium-sphere-magnets/3mm-sphere-magnet/ (Not sponsorship) - a 45mm length metal rod, with 3mm in diameter. I used a 2.7mm, since I don't have a press to fit the bearings tightly in the rod. By rule, the tighter, the better. I think 2.8mm will work. I don't have a lathe either. - 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 discs were 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. Due to the lose magnets, 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…