The original idea is fine but I didn't like that the ring rotates as if the bearings are rusty. I kept the gears but made a new design of the upper and bottom parts in Freecad to make the gears more loose. I also made a hole in the middle as a finger grip. You can see the result in the video: https://www.youtube.com/watch?v=CPdHSLgoxDc
I uploaded stl version and freecad version in case somebody wants to find a better tolerance to improve my results (my version rotates a couple of seconds, it can be probably made better but I'm fine with it). Hint: play with 39.4 value in freecad scetch - increase it to make it more stiff or decrease it to make it more loose (the result may depend on your printer). After you update this value, the other values will be calculated automatically to adjust new size of the covers, so there is no need to redesign the whole model.
The top and bottom covers are optimized for 0.28 layer height.
The gears are better to be printed with 0.2 layer height.
The author remixed this model.