Extruder (3D printing)

Additionally, they reduce the mass of the extrusion carriage because it doesn't have to hold a stepper motor.

Another disadvantage is that the feeding distance is relatively long, and thus the resistance is high, meaning the stepping motor of extrusion is required to have a higher torque.

Direct-drive designs have several advantages, and typically give better extrusion, faster retraction, are able to print more types of filaments, and can use a smaller and lighter motor due to the short distance to the nozzle.

[4] One typical disadvantage of direct-drive extruders is the added mass to the hotend, compared to a typical Bowden extruder, which may cause more vibrations so that the direct-drive printhead has to move slower, which can affect print speed.

Another typical disadvantage is more complex maintenance[4] due to tight packaging of many components in the hotend.

On a Bowden design, the feeding mechanism (here indicated with two roller wheels) often sits relatively far away from the hot end part of the extruder.
A direct drive extruder