The file 'Square Shaft Gear For Mouth/eye Moving Animatronic Toys 3D Printer Model' is (stl) file type, size is 12.9KB.
This is the "square shaft" gear used in mouth opening-eye rolling mechanisms, it has bigger teeth than normal 0.5mm modulus gears, this is why it had to be designed.
I used it in a christmas donkey made by Krea(which i recently powered on after a couple years and said gear broke in half right away), but i'm sure most mechanisms of this kind will use the same gear. it's the very last gear, placed on the square shaft that connects to the jaw pieces outside the gearbox.
donkeymouthgear.stl | 61.6KB |