When printing using any type of FDM printer, it’s important to understand that the software controlling the printer calculates the extrusion volume based on the filament diameter, the diameter of your extruder nozzle and the extrusion speed (commonly referred to as flow rate – in mm/s). In essence, your printer controls the volume of plastic that is pushed out of the nozzle by turning the extruder wheel and pushing a certain length of filament down the hot end. If you have an irregular diameter, the volume of extruded plastic varies and the software can’t and won’t adjust the extrusion length to compensate for the variation. Instead, it will keep on printing expecting a certain ‘theoretical’ amount of plastic to come out. This is what we refer to as ‘inconsistent extrusion’.

Inconsistent filament diameter raises to serious issues like extruder failure where in no plastic makes it to the hot end, this can occur if your filament suddenly becomes too thin for the tensioning mechanism and there is less pressure gripping the filament.Another effect of a decrease in filament diameter is that back flow could occur in the hot end (hindering plastic delivery to the head)

 

Posted in: 3D Filaments