cycloid gear reducer with a ratio of 15 to 1 , .stl , .obj , .fbx , .dae, be careful of the scale depending on your 3d printer and filament, you may nedd to tweek the scale of the gear and the pinion
STL (Stereolithography, filesize: 8.4 MB), OBJ (OBJ, filesize: 8.4 MB), FBX (Autodesk FBX, filesize: 8.4 MB), DAE (Collada, filesize: 8.4 MB)