In 3D Printing, an extruder is a unit inside the Toolhead that is designed to intake the filament from the top, run it down through the Extrusion System and at the end, project the filament as a smaller diameter out the nozzle. During this process, the filament is grabbed by a gear, pulled down through the chamber and then heated to a very hot temperature, usually somewhere near 200 Degrees Celsius. This then allows the material to melt, allowing the rest of the system to continue pushing it down and out a nozzle that is smaller than the original diameter of the filament. While the filament is still malleable, the Toolhead moves to project the recently extruded plastic where it wants.

Crucial parts of an extruder system include:

• The Motor, which is what drives the material down into the rest of the extruder by spinning the Drive Gear(s). See more on Extruders - Gears.

• The Drive Gear, which grips the filament in the filament path and forces it to go down towards the nozzle. This gear may be connected to another gear, or it may be spinning on the motor axle itself.

• The Hot End, the lower end of the Toolhead, where all of the heating elements, thermistors, and other heat-related elements go. This is the “business end” of the Toolhead because this where all of the processes that allow the plastic to be extruded correctly take place.

• Cooling Systems: The fans and regulatory systems that keep the Hot End at a stable temperature during printing and prevent overheating.

Overall, the extruder system allows the filament to be extruded and creates all of the wonderful 3D prints we know and love.