Abstract: A method of printing a multi-material part in a layer-wise manner with an extrusion-based 3D printer includes providing a sliced digital model of a multi-material part and determining a number of materials in each of the slices of the digital mode. The method includes utilizing a digital model of a purge tower having N subdivisions having a closed geometry, wherein N is the number of print heads needed to print the part that is greater than or equal to three, each adjacent subdivision contact one another along an interface and assigning each print head to one subdivision and to tool paths forming the one subdivision in each layer. The method includes reassigning the assigned subdivision within the purge tower of an inactive print head in a layer to a print head that is active in the layer of the multi-material part.

Abstract: A 3D printer includes a gantry configured to move in a plane substantially parallel to a x-y build plane and a print head configured to extrude molten material to print a 3D part in a layer-by-layer process. The 3D printer includes a platen configured to support the part being printed in the layer by layer process and positionable with a primary Z positioner along a z-axis substantially normal to the x-y build plane. The 3D printer includes a local Z positioner moved by the gantry, the local Z positioner comprising a linear motor configured to move the print head in the z-direction and having an operable range of motion extending from a nominal build position at which a nozzle of the print head is positioned in the x-y build plane to a raised position above the x-y build plane.

Abstract: A 3D printer includes a gantry configured to move in a plane substantially parallel to a x-y build plane and a print head configured to extrude molten material to print a 3D part in a layer-by-layer process. The 3D printer includes a platen configured to support the part being printed in the layer by layer process and positionable with a primary Z positioner along a z-axis substantially normal to the x-y build plane. The 3D printer includes a local Z positioner moved by the gantry, the local Z positioner comprising a linear motor configured to move the print head in the z-direction and having an operable range of motion extending from a nominal build position at which a nozzle of the print head is positioned in the x-y build plane to a raised position above the x-y build plane.

Abstract: A method of moving a print head between a plurality of partitioned chambers in a 3D printer includes providing the 3D printer having a thermal barrier having an area defined by a length and width, wherein a print head nozzle can be positioned through the thermal barrier along the width or the length and at least two partitioned chambers below the area of the thermal barrier, wherein a first chamber comprises a printing chamber and a second chamber comprises a chamber providing another functionality. The method includes raising the print head in a z direction from the second chamber to above the thermal barrier and moving the print head in a x-y direction from above the second chamber over the partition to a location above the first chamber. The method also includes lowering the print head in the z direction and into the first chamber such that an extrusion port of a nozzle of the print head is proximate a x-y print plane.

Abstract: A 3D printer includes a gantry configured to move in a plane and in a direction substantially normal to the plane and at least one print head carried by the gantry, the at least on print head comprising an extrusion nozzle at a bottom end. The 3D printer includes a plurality of partitioned chambers accessible by the at least one print head, each of the partitioned chambers having an upper edge defining an opening into each of the plurality of chambers, and a platen within a first chamber of the plurality of chambers, the platen configured to receive material from the print head to print the 3D part.

Abstract: A 3D printer includes a gantry configured to move in a plane substantially parallel to a x-y build plane and a print head configured to extrude molten material to print a 3D part in a layer-by-layer process. The 3D printer includes a platen configured to support the part being printed in the layer by layer process and positionable with a primary Z positioner along a z-axis substantially normal to the x-y build plane. The 3D printer includes a local Z positioner moved by the gantry, the local Z positioner comprising a linear motor configured to move the print head in the z-direction and having an operable range of motion extending from a nominal build position at which a nozzle of the print head is positioned in the x-y build plane to a raised position above the x-y build plane.