We have already seen how to activate/deactivate the retraction in Cura 3D.
Today, we’re gonna learn more about other specific retraction parameters, like minimum travel, enable cooling, minimal extrusion before retracting, and z -hop.
The retraction speed is always measured mm/s and, basically, is how fast the extruder motor rotates in the opposite direction, allowing the filament to go backward in the hotend.
It’s important to set the right speed measure. The retraction is too fast, meaning over 40mm/s, and the filament gets damaged or blocked in.
The retraction distance defines the length of filament to be retracted by the extruder motor. It goes from 2.5mm to 8mm, based on how far the nozzle and the hotend are.
The longer the distance between the extruder motor and hotend, the higher the value. This is to avoid the annoying strings the printer leaves when it goes from point A to point B, crossing an empty space.
The printers with hotend and motor extruder close, generally, have a 3mm standard value. The ones with a Bowden extruder (hotend and motor extruder distant) have a 7mm value.
In the Expert Configuration, we can modify a couple of important settings to improve the safety of our prints.
Minimum Travel is like a threshold, under which when the printer moves without extruding, there is no retraction.
For example, set it to 2mm so that you’re sure every movement under that value will be avoided, saving up time and useless actions.
Z-Hop raises the nozzle by a small amount when it’s moving the head to a different location. It’s mostly used to prevent the nozzle from dragging across the surface of the 3D entity or leaving “blobs” or scratches on the print surface. For prints with lots of retractions/travel moves, Z Hop can increase the print time.