If you fit motors to the microscope, the motors need small gears on them to mesh with the large gears that control the microscope. You need three gears, and the STL file provides all 3. NB the gears have a flat lip around the bottom - this is to help them stick to the print bed and avoid the teeth being distorted, so it should be at the bottom when printed.

STL File

  • small_gears.stl