Based on this thing: 213946. Also found on Printables 240274. I was surprised to not see one on here so here it is.

Blank model, dropped onto two plates.

I printed gears in Extra fine default settings, and then the pins and center in Strength. No support needed. If you have adhesion issues add a brim.

I have made a lot of these, people at my work love them. I add a bit of lithium grease on each pin before inserting to make it easier to spin in the beginning. The more you spin this the smoother it gets, I have one on my desk for about 2 years now and it's super smooth.

8 pins, 4 small gears, 4 big gears, and 1 center piece. I'll pop all 8 pins into the center piece. Then start with the larger gears, get proper alignment as you go and before you click in the last gear.