Retraction and Displacements in FDM 3D Printing: All You Need to Know

Modeling is an important step in additive manufacturing. Once you have decided on a design, you need to make sure that everything works correctly by configuring and adjusting the printing parameters. These configurations will be carried out in the slicer that is compatible with the machine in question, enabling users to reduce certain printing errors to a minimum. Popular solutions on the market include Cura and PrusaSlicer. When using FDM 3D printing, one of the most important points to consider is the movement of the head in the print zone. To further explore this, we took a closer look at the types of displacement that are possible in 3D printing, as well the role of retraction in particular.

What Is Retraction in 3D Printing?

To begin, we first need to talk about retraction. This is a mechanism adopted by the 3D printer when its head has to move between two parts of the part to be printed. Retraction essentially pulls the filament back to prevent the material from flowing during the movements and displacements performed by the vacuum extruder during the 3D printing process, thus reducing the pressure inside the nozzle. If retraction is not applied, the extruded material may remain suspended between the 3D printed parts.

The extruder is capable of retracting a portion of filament to prevent it from flowing between printhead movements.

The parameters configuring this related to the retraction distance itself, which varies according to the material and the type of extrusion system chosen, especially when referring to the use of a Bowden or direct drive extruder. If we use the Bowden extruder, the movements will be cleaner because the filament will pass through a tube called a Bowden and the extruder will be mounted directly on the printer chassis. On the other hand, if we opt for the direct drive extruder, retraction will be better and the result more precise, as the filament will be pushed directly towards the nozzle.