I wanted to devise a gear train which had an output shaft in the same position as if a worm on the motor shaft was meshed with a 19t pinion above it, without using a worm gear. The picture shows how this is achieved. The only gear you can't see is a 15t pinions between the motor side plates which meshes with the 38t gear. The overall reduction is 22.8:1. If the motor is mounted on its side in a 3.5" wide chassis, butted up against one edge, the output shaft will be along the centre line of the chassis.