Abstract: An additive manufacturing system opens the valves in an extruder needed to form a swath and operates an actuator to move the extruder through a transition region with those valves open to establish an amount of extrusion material between a faceplate of the extruder and a portion of an object being formed that is adequate for formation of a swath. The length of the transition region is determined with reference to a viscosity of the material being extruded and a speed at which the extruder is moved to form the swath. The transition region can be perpendicular to a path of the extruder to form the swath or aligned with the path of the extruder to form the swath.

Abstract: An extruder has a valve assembly configured to move pins to open and close the nozzles in a multi-nozzle extruder head independently. The pins of the valve assembly that are driven by actuators into and out of engagement with nozzles in the extruder head are positioned within sleeves that extend between the valve assembly and the extruder head. A gap is provided between the extruder head and the end of the sleeves proximate the extruder head to enable thermoplastic material leaking from the extruder that contacts the pins to remain in a melted or plastic state so the thermoplastic material does not interfere with the movement of the pins.

Abstract: A jetting assembly that can be used to print a high-temperature print material such as a metal or metal alloy, an aqueous ink, or another material, includes an actuator for heating a gas such as a non-volatile gas within a gas cavity. The actuator rapidly heats the gas within the gas cavity, which rapidly increases a volume of the gas, thereby applying a pressure to the print material within an expansion channel that is in fluid communication with the gas cavity. In turn, the print material within the expansion channel applies a pressure to the print material within a nozzle bore, which forces a drop of the print material from a nozzle. The jetting assembly further includes a supply inlet that supplies the print material to the expansion chamber and the nozzle bore, for example, from a reservoir.

Abstract: A controller operates a first actuator to produce relative movement between a multi-nozzle extrusion printhead and a support member along a predetermined path for one layer of a three-dimensional printed object. The multi-nozzle extrusion printhead includes a housing with a chamber, a valve assembly having a plurality of passageways, and a planar member having a plurality of nozzles. The passageways of the valve assembly and the nozzles of the planar member are connected to one another in a one-to-one correspondence and valve members of the valve assembly are operated to open and close melted extruded material flow to the nozzles selectively and independently.

Abstract: An extruder has a valve assembly configured to move pins to open and close the nozzles in a multi-nozzle extruder head independently. The pins of the valve assembly that are driven by actuators into and out of engagement with nozzles in the extruder head are positioned within sleeves that extend between the valve assembly and the extruder head. A gap is provided between the extruder head and the end of the sleeves proximate the extruder head to enable thermoplastic material leaking from the extruder that contacts the pins to remain in a melted or plastic state so the thermoplastic material does not interfere with the movement of the pins.

Abstract: A method for printing a structure, the structure including a plurality of pillars. The method for printing can include ejecting only a first drop of a print material such as a liquid metal sequentially at each of a plurality of pillar locations, then ejecting only a second drop of the print material sequentially onto the first drop at each of the plurality of print locations. Additional drops can be ejected at two or more of the pillar locations to form the plurality of pillars. Ejecting only a first drop at each pillar location allows the first drop to cure (i.e., cool or dry) before ejecting the second drop. The printer continues printing while the drops cure, thus improving processing efficiency and increasing production throughput.

Abstract: A method operates a three-dimensional (3D) metal object manufacturing system to compensate for displacement errors that occur during object formation. In the method, image data of a metal object being formed by the 3D metal object manufacturing system is generated prior to completion of the metal object and compared to original 3D object design data of the object to identify one or more displacement errors. For the displacement errors outside a predetermined difference range, the method modifies machine-ready instructions for forming metal object layers not yet formed to compensate for the identified displacement errors and operates the 3D metal object manufacturing system using the modified machine-ready instructions.

Abstract: A three-dimensional (3D) printer includes an ejector and a heating element configured to heat a solid printing material in the ejector, thereby causing the solid printing material to change to a liquid printing material within the ejector. The 3D printer also includes a coil wrapped at least partially around the ejector. The 3D printer also includes a power source configured to supply one or more pulses of power to the coil, which cause one or more drops of the liquid printing material to flow out of the ejector through a nozzle of the ejector. The 3D printer also includes a gas-controlling device configured to control a gas in the 3D printer.

Abstract: A method of operating an additive manufacturing system feeds solid extrusion material into a heater using a slip clutch coupled to an actuator of a mechanical driver to supply thermoplastic material into a manifold in an extruder head. The method sets a speed of the actuator so the actuator operates at a rotational speed that is slightly greater than the rotational speed of the mechanical mover. This method helps maintain the pressure of the thermoplastic material in the manifold of the extruder head in a predetermined range no matter how many nozzles are opened in the extruder head.

Abstract: An extruder head has an arrangement of multiple nozzles in the faceplate that avoids aligning the multiple nozzles at angular orientations from the 0°-180° axis and 90°-270° axis intersection at the center of the faceplate. The extruder head includes a housing having a faceplate with a plurality of nozzles that are equally spaced from one another when the nozzles are projected onto a first axis in a plane of the faceplate and the nozzles are equally spaced from one another when projected onto a second axis in the plane of the faceplate that is orthogonal to the first axis. Movement of the extruder head along any angular path from the intersection of the first axis and the second axis in the plane of the faceplate enables at least one nozzle in the plurality of nozzles to not be aligned with any other nozzle.

Abstract: An additive manufacturing system includes a heater for converting a filament of extrusion material into thermoplastic material. The heater has a channel configured to change the cross-sectional shape of the filament to a cross-sectional shape that has a greater surface area than the surface area of the filament before the heater receives the filament. The channel of the heater can also be configured to drive the center portion of the filament toward the heated walls of the channel and to mix thermoplastic material in the channel while exposing the center portion of the filament to the heated wall of the channel.

Abstract: An additive manufacturing system and method for improving the certainty of removing or etching excess substrate from a stack of printed substrate slices to arrive at a 3D object. The approach includes printing a pseudo image as a shell layer around a desired object slice with less polymer (e.g., thermoplastic) material than the 3D object solid layer slice. This slows the etching process when this pseudo image is reached. The pseudo image may be printed to surround the object polymer image on a printed substrate sheet as a shell that provides notice during the excess substrate removal/cleaning process that the desired polymer image is nearby and extra care must be taken to avoid removal of the desired polymer image. The pseudo image may have a 3D patterned surface that can be recognized by a person doing the sandblasting or recognized automatically by an automated 3D object finisher.

Abstract: An additive manufacturing system operates an actuator to move an extruder with reference to a selected first zig-zag pattern to sparsely fill an interior region of an object by extruding a swath of thermoplastic material that has straight portions connected by angled portions. After a first pass using the first zig-zag pattern is completed, a second zig-zag pattern is used to form a complementary swath that forms rigid structure with the first swath. Use of the two patterns is alternated to sparsely fill the interior region in multiple layers of the object until a predetermined distance from a solid fill structure or surface is detected. Transition patterns are then used to increase the density of the swaths in the interior region in the next successive layers of the object until the layer is reached where a solid fill surface is formed over the swaths formed using the transition patterns.

Abstract: An apparatus includes a heater for converting a filament of extrusion material into thermoplastic material. The heater has a channel configured to change the cross-sectional shape of the filament to a cross-sectional shape that has a greater surface area than the surface area of the filament before the heater receives the filament. The channel of the heater can also be configured to drive the center portion of the filament toward the heated walls of the channel and to mix thermoplastic material in the channel while exposing the center portion of the filament to the heated wall of the channel.

Abstract: A method for identifying an angular deviation in the orientation of a multi-nozzle extruder includes moving the multi-nozzle extruder in a first process direction to form a first extrusion material swath and moving the multi-nozzle extruder in a second process direction opposing the first process direction to form a second extrusion material swath. The method further includes identifying widths and heights of the swaths from scanned image data and identifying a component of angular deviation for the multi-nozzle extruder with reference to at least one of a difference between the first swath width and the second swath width and another difference between the first swath height and the second swath height.

Abstract: The nozzles of a MHD liquid metal ejector/printhead can be clogged by contaminants in the liquid metal. Typically, these contaminants are in the form of small particles of aggregates of particles, such as metal oxides, that are insoluble in the liquid metal. Possible cleaning methods include mechanically removing the clogging material, such as by using a physical device to dislodge the clogging material and remove it; chemically removing the clogging material, such as by using selected chemicals/flux to chemically react with the clogging material; using ultrasound to break/remove the clogging material; and providing reversed and/or oscillating flow of material through the nozzle.

Abstract: A method operates a three-dimensional (3D) metal object manufacturing system to compensate for errors that occur during object formation. In the method, thermal image data and dimensional image data of a metal object being formed by the 3D metal object manufacturing system is generated prior to completion of the metal object. Thermal conditions are identified from these data and compared to predetermined ranges corresponding to the identified thermal conditions to identify one or more errors. For identified errors outside a corresponding predetermined difference range, the method performs an error compensation technique. The error compensation includes modification of a surface data model, modification of machine-ready instructions, or operation of a subtractive device.

Abstract: A system for producing three-dimensional objects forms fluid paths within the support structure to facilitate the removal of the support structure following manufacture of the object. The system includes a first ejector configured to eject a first material towards a platen to form an object, a second ejector configured to eject a second material towards the platen to form support for portions of the object, at least one portion of the support having a body with at least one fluid path that connects at least one opening in the body to at least one other opening in the body, and a fluid source that connects to the at least one fluid path of the support to enable fluid to flow through the at least one fluid path to remove at least an inner portion of the support from the object.

Abstract: An additive manufacturing system opens the valves in an extruder needed to form a swath and operates an actuator to move the extruder through a transition region with those valves open to establish an amount of extrusion material between a faceplate of the extruder and a portion of an object being formed that is adequate for formation of a swath. The length of the transition region is determined with reference to a viscosity of the material being extruded and a speed at which the extruder is moved to form the swath. The transition region can be perpendicular to a path of the extruder to form the swath or aligned with the path of the extruder to form the swath.

Abstract: A three-dimensional object printer is configured to generate a printed predetermined test pattern on a substrate in the printer with a plurality of ejectors in a printhead. An image sensor generates image data of the printed test pattern and a controller identifies a z-axis distance between the printhead and the substrate using a dispersion identified between cross-process direction distances separating printed marks in the test pattern.