You may have heard of Bowden tubes, but what are they really? How are they different from other extruders, and which should you choose? Find out in this guide to Bowden tubes. The extruder, where filament is melted and pushed out, is a key component in any FDM 3D printer. Extruders consist of a stepper motor and a hot end. The stepper motor grips the filament and feeds it to the hot end, which melts the plastic onto the bed. There are two main types of extruders: direct and Bowden. A direct drive extruder has the stepper motor on the print head itself, so filament gets pushed directly into the hot end. This means the print head has to carry the weight of the stepper motor as it moves along the x-axis. The Bowden extruder has the motor on the frame, far away from the print head. This is where the Bowden tube comes in. The motor feeds the filament through a Bowden tube (usually made of PTFE plastic) to the print head. The tube guides the filament from the fixed motor to the moving hot end, protecting the plastic from snapping or being stretched by constant movement. Flexible and rubber-like filaments can be difficult to print with Bowden tubes. Since these filaments aren’t rigid,...