Fixed printhead fused filament fabrication printer and method

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#Not applicable.

#The present invention relates to extrusion-based 3-D printers, termed fused deposition modeling or fused filament fabrication printers, in general and more particularly to printers using a printhead which applies layers of thermoplastic (e. g. ABS, HDPE, PLA, PVA) to create models, prototypes, patterns, and production parts.

#FIG. 1 is a front isometric view of the fused filament fabrication printer of this invention.

#FIG. 2 is an exploded isometric view of the fused filament fabrication printer of FIG. 1.

#FIG. 3 is a fragmentary isometric view of the printhead mounting fixture, build platform, and a plurality of printheads of the fused filament fabrication printer of this invention.

#Referring more particularly to FIGS. 1-4 wherein like numbers refer to similar parts, a fused filament fabrication printer 20 is shown in FIG. 1. The printer 20 provides movement along three degrees of freedom to position various portions 22 of a printer build platform 24 beneath a plurality of printheads 26. The printheads 26 have tips 34 through which thermoplastic polymers, or metals are extruded. The three degrees of freedom start with a first degree of freedom: rotation of the build platform 24. The build platform defines a start-print plane or surface 32. A second degree of freedom is provided by linear motion along a radius or y-axis 36 perpendicular to the z-axis 28. A third degree of freedom is provided by linear motion of the printer platform in a Z-direction along the z-axis 28. The build platform 24 is moved in the Z-direction so the surface 32 occupies parallel planes, each parallel to a plane defined by the tips 34 of the printheads 26.

#The indexing of the three degrees of freedom in combination with the controlled turning on and off of the extrusion process in the printhead or printheads generates the printed object or model 31.

#As shown in FIG. 1, three degrees of motion can be provided by a comparatively simple structure 38. The structure 38 includes four vertical supports 40 such as the angle irons shown. The supports 40 are mounted to a base 42 comprised of a first pedestal 44 and a second pedestal 46 held in spaced apart array by two lower horizontal supports 48. Two of the vertical supports 40 are mounted to each of the pedestals 44, 46. The vertical supports have upper ends to which are mounted a first motor mounting plate 50, and a second motor mounting plate 52 which are positioned over the pedestals 44, 46 respectively. The motor mounting plates 50, 52 are correspondingly spaced apart by upper horizontal supports 54. Between each of the pedestals 44, 46 and the corresponding overlying motor mounting plates 50, 52 is a lead screw 56 and a cylindrical way rod 58. The way rods 58 extend between the mounting plates 50, 52 and the corresponding underlying pedestals 44, 46, and are fixedly mounted to the plates and the pedestals. The lead screws 56 are mounted at first ends 60 to the pedestals 44, 46 by bearings 62, and are mounted to the overlying mounting plates 50, 52 by stepper motors 64. The motors drive directly or indirectly the lead screws 56.