The main challenge was balancing tolerance, durability, and smooth rotation at this scale. We went through multiple prototypes dealing with ball size, raceway depth, and surface finishing before getting consistent 20s spins.

Would love feedback from anyone who’s worked on ultra-compact mechanical systems or precision manufacturing.

If you’re curious, the project is live on Kickstarter: https://www.kickstarter.com/projects/cooloze/spinitytm-beari...