Posted on 08/01/2018
What is retraction in 3D printing? Definition and adjustments
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This article tries to clarify the concept of retraction in 3D printing as it's a very important parameter to achieve quality prints, without material depositions on the exterior face of the model, or threads between pieces that are printed at the same time.

Retraction is the recoil movement of the filament necessary to prevent dripping of material during movements and displacements that the vacuum extruder performs during 3D printing.

The parameters that configure the retraction are:

  • Retraction distance: Length of material that recedes in the retraction process. It varies depending on the type of material, the type of extrusion system (Direct or Bowden) and the type of HotEnd. For flexible materials, especially for the TPE type (Filaflex), retraction must be deactivated to prevent the filament from coiling on the extruder pinion.
  •  Retraction speed: Speed at which the extruder motor drives back the filament. With this parameter it's necessary to be very careful if high speeds are used (greater than 70mm/s) because it can mark the filament in such a way that it's unusable to continue the 3D printing.
  •  Minimum displacement: Minimum length from which you want the retraction to take place.
  •  Enable combining: By activating this parameter, which is in the section of advanced options of retraction of the program of lamination that is used (Cura, Simplify3D, Slicer, etc),  apart from performing the retraction, the HotEnd is prevented from moving over holes. With this material remains are avoided in the faces seen from internal parts of the pieces.
  • Z-axis elevation when retracted (Lift z): At the same time that the retraction occurs, the HotEnd moves on the z axis the indicated distance. This elevation is only necessary in the case of making pieces with many details and with small areas of great detail to avoid leaving traces of material right in that area. If you need to use this parameter, we recommend using the same distance as the layer height.

With the appropriate adjustment of the above parameters you get the ideal retraction for your 3D printer.

Unfortunately there is no formula to find the exact value, but each 3D printer and each extruder needs a particular value. The following table contains recommended values of length and retraction speed for the 3D printer depending on the type of extruder used, which are a good starting point to adjust them to your particular case:

Retraction parameters

Image 1: Retraction parameters

 The values of the table are entered in the retraction section of the lamination software that is used, in our case, Cura 3D, is within the category of material.

Retraction in 3D printing

Image 2: Retraction configuration in Cura 3

 Care must be taken when varying the length parameter, because if it is increased too much (20 mm in a direct extruder), it will cause a discontinuous flow and thus gaps in the piece being printed.

 Once all the parameters that configure the retraction are understood and based on the values that we have provided, each user will obtain their ideal configuration by simply making small adjustments.

Comments (4)

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      roberto abr 6, 2020

      Tambien interviene temperatura, a menor temperatura filamento menos fluido por lo tanto menos hilillos

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        Antonio sep 13, 2021

        Tengo una ender 3 max. Y estoy utilizando el pla plus de esun y tengo un lío con las retracciones. Me daca hilo. Si alguien me puede ayudar para que esto no me pase estiy buscando la configuración perfecta. Gracias de antemano

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      Miller Guevara abr 30, 2021

      Hola me gustaría saber si la pre configuración de cura por las maquinas es ideal ó es una estándar y se debe modificar según las datos que nos ofreces que trae cura.
      Es posible que actualicen esta información con la ultima versión de cura.

      • Avatar
        Filament2print may 6, 2021

        Hola, miller. La preconfiguración de las máquinas siempre es un estándar, puesto que los parámetros varían mucho en función del material empleado, temperatura ambiente, y otros factores. Lo ideal es modificarlos hasta encontrar los valores óptimos.

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