This is a thing that reminds me back in time. When i was a little kid i looked for things like this with trains. When i saw the competition i thought that i maybe can design a thing like this. Some time exprimenting with the settings and how i in the best way i can design the parts.
Somehow you need to print one of each part, but 8 of the skull with pin. You put them in place in the 8 holes in the big gear, then you put the gear in place in the base. You install the small gear in the back of the base AFTER installing the big gear. Now you can rotate the small gear and the skulls on the big gear should also rotate.
List of thangs you have to print: One Base_v2 One big_gear_v2 One Small gear Eight Skull with pin I recommend you print with support on all of the thangs but you dont need it on the big gear.