3D printer and printhead unit with multiple filaments

摘要

A fused filament fabrication printer has a fixed extrusion module having multiple printheads having print tips. The fixed arrangement of the printing heads allows the close spacing of multiple print tips in a printhead unit, and the simple routing of multiple plastic or metal filaments to the individual printing heads. The closely spaced print tips in the printhead unit share common components. An exemplary printhead unit has four printing heads which share a common heating block and heating block temperature sensor. The heating block incorporates a group of four print tips evenly spaced along a line. Each printing head has a separate filament which is controlled and driven by its own stepper motor through the heating block to one of the print tips. Printing of a part is by control of individual stepper motors which drive filaments through the heating block and through one of the printing tips.

主权项

1. A fused filament fabrication printhead unit comprising:
a fixture; a plurality of stepper motors mounted to the fixture, each stepper motor of the plurality of stepper motors having a motor shaft and a filament drive gear mounted to the motor shaft; portions of the fixture forming a plurality of filament guide paths, each of the plurality of filament guide paths arranged to guide a filament through the fixture and into engagement with one of the filament drive gears, such that rotation of the filament drive gear drives the filament along one of the plurality of filament guide paths; an extrusion module mounted to the fixture in filament receiving relation to the filament guide paths, the extrusion module further comprising:
at least one insulating standoff having a thermal conductivity of less than 5 W/(m·K) mounted to the fixture and supporting a nozzle block with a thermal conductivity greater than 25 W/(m·K);a heating element arranged in thermal contact with the nozzle block for heating the nozzle block;wherein portions of the nozzle block form a plurality of heated guide paths, each heated guide path leading to portions of the nozzle block forming a nozzle with a print tip;a plurality of thermally insulating filament guides having a thermal conductivity of less than 5 W/(m·K), each of the thermally insulating filament guides connecting one of the filament guide paths to one of the heated guide paths.