Gear train created in Blender 2.83. Simulation created using bleder's rigid body simulations. Model only includes gears, and no materials. The vertex and polygon numbers are for all 3 gears. STL files for 3D printing are also included.
BLEND (Blender, filesize: 4.14 MB), OBJ (OBJ, filesize: 2.9 MB), FBX (Autodesk FBX, filesize: 1.96 MB), STL (Stereolithography, filesize: 2.29 MB)