The Endless Gears Busy Board model is fantastic.
I found that as I had printed the base board with .300mm layers, the interior holes were tight for the gears.
I took the 48 tooth gear in the set and scaled the pin down by 5% and also made the top of the gear more flat to aid in printing without supports.
Matt's Hub PLA Red
100% infill
.150 mm layers
MK3S
The author remixed this model.