Abstract: A fused filament fabrication device comprising a print head having an inlet for receiving a filament of printable material, a melt chamber and an outlet for letting out flowable printable material. A filament feeder is arranged to feed the filament into the print head and arranged to retract the filament from the print head. A controller is configured to a) order the filament feeder to retract the filament over a first distance, wherein the filament is not yet broken; b) stop heating the melt chamber; c) cooling the filament to a predefined temperature, and then d) order the filament feeder to further retract the filament over a second distance so as to break the filament. By letting the filament in the print head cool off to a temperature at which the print material hardens, a controlled breakage can be realized without the occurrence of a thread at the retracted filament.

Abstract: A fused filament fabrication device comprising a print head having an inlet for receiving a filament of printable material, a melt chamber and an outlet for letting out flowable printable material. A filament feeder is arranged to feed the filament into the print head and arranged to retract the filament from the print head. A controller is configured to a) order the filament feeder to retract the filament over a first distance, wherein the filament is not yet broken; b) stop heating the melt chamber; c) cooling the filament to a predefined temperature, and then d) order the filament feeder to further retract the filament over a second distance so as to break the filament. By letting the filament in the print head cool off to a temperature at which the print material hardens, a controlled breakage can be realized without the occurrence of a thread at the retracted filament.