Here's my finished clock. Thought I would do this one in PETG. Turned out nice. I did make a couple changes. Modded the hands from the smaller version since I like them better. I also modded the slip clutch gears so they had a full flat surface on each one. PETG is slippery and this helped a lot. If you use the listed OSOYOO Arduino Nano boards don't forget to load the OSOYOO Board files. I programmed the board, it ran super slow. I then realized these require there own files listed here https://osoyoo.com/2022/08/11/arduino-hardware-support-package-for-lgt-nano/ I also put a piece of tape over the LEDs on the Nano because they were making a light show through the PETG case. All good after that...
Interesting. I wonder if the OSOYOO boards default to an ultra low power mode running at a low clock rate. Glad you found a solution and posted about it.