TT motor gearbox reducer

I. Design inspiration

This is an external reduction gear module adapted for standard TT DC motors. It features a 10-tooth active gear paired with an 18-tooth large driven gear, with a reduction ratio of 1:1.8. The large gear pin shaft is cut from 1.75mm 3D printing material and inserted for positioning. The split housing is equipped with a transparent cover plate. It can be used as a power modification part for robot cars or as a teaching aid for gear transmission training.

II. 3D printing process

The box, cover plate, and gears are printed using wear-resistant PETG, with a smooth clearance of 0.2mm reserved for gear meshing. The large gear shaft hole is designed to fit a 1.75mm filament rod. After cutting, it can be directly inserted as a pin shaft, eliminating the need for a metal shaft. The motor compartment precisely fits the TT motor, with fixing ears on the sides. There is no large area of overhang, with only minimal support from the shaft column, making the printing and assembly process highly accessible.

III. Structure and Function

The TT motor drives a 10-tooth small gear, which in turn drives an 18-tooth large gear to achieve speed reduction and torque increase. The large gear relies on a 1.75mm consumables rod that has been cut to serve as a rotating pin shaft, making installation and removal convenient. The transparent cover allows for direct observation of gear engagement, and the enclosure includes pre-installed mounting holes, allowing it to be fixed to carts, mechanical grippers, and other DIY mechanisms. It is suitable for both teaching demonstrations and power output for small-scale equipment.