Main shaft assembly - Bondtech

One of the most important components of FDM 3D printers is the extruder system, which is responsible for pulling the filament to the hotend. Inside the extruder there are 3 main components: motor, pressure gears and drive gear.

The rotational speed emitted by the extruder motor is much higher than what is actually needed in the assembly to extrude the filament. Therefore, it is necessary to reduce the initial speed emitted.

To achieve the ideal rotational speed and transmit it to the sprockets that drive the filament in the FDM 3D printer, an intermediate assembly consisting of a ring gear and a shaft is used. The ring gear has a higher number of teeth than the main sprocket to reduce rotational speed and increase torque. This rotation is transmitted along the shaft that forms the assembly, and the primary drive gear is inserted at the end to drive the filament.

This ring gear and shaft assembly is a genuine replacement part compatible with Bondtech Mini Geared (BMG), SingleDirect and DualDirect, and includes the set screw for the 1.75 / 5.0 primary drive gear.