Abstract: According to some aspects, a de-powdering subsystem for an additive fabrication system is described. The de-powdering subsystem may comprise a bath subsystem. The bath subsystem may comprise a reservoir configured to contain a liquid and to accept objects to be de-powdered into the liquid, and an agitation facility configured to cause currents within the liquid. The agitator facility may be at least one of (i) a pump configured to circulate the liquid within the reservoir, (ii) a heating element configured to generate convection currents in the liquid, and (iii) a stirrer driven through a linkage to a motor. The bath subsystem may comprise at least one ultrasonic transducer configured to apply ultrasonic vibrations to the liquid within the reservoir.

Abstract: A system and corresponding method to move a rod of build material in a three-dimensional (3D) printing system uses a pusher. The rod of build material has distal and proximal ends relative to an extrusion head. The distal and proximal ends having distal and proximal end surfaces, respectively. The pusher engages with the rod and applies an axial force to at least a portion of the distal end surface of the rod for at least a portion of a path the rod travels toward the extrusion head. The axial force actuates the rod of build material without alteration, such as by shaving, fracturing, or otherwise deforming the rod of build material.

Abstract: Complexity of a geometry of a desired (i.e., target) three-dimensional (3D) object being produced by an additive manufacturing system, as well as atypical behavior of the processes employed by such a system, pose challenges for producing a final version of the desired 3D object with fidelity relative to the desired object. An example embodiment enables such challenges to be overcome as a function of feedback to enable the final version to be produced with fidelity. The feedback may be at least one value that is associated with at least one characteristic of a printed object following processing of the printed object. Such feedback may be obtained as part of a calibration process of the 3D printing system or as part of an operational process of the 3D printing system.

Abstract: Complexity of a geometry of a desired (i.e., target) three-dimensional (3D) object being produced by an additive manufacturing system, as well as atypical behavior of the processes employed by such a system, pose challenges for producing a final version of the desired 3D object with fidelity relative to the desired object. An example embodiment enables such challenges to be overcome as a function of feedback to enable the final version to be produced with fidelity. The feedback may be at least one value that is associated with at least one characteristic of a printed object following processing of the printed object. Such feedback may be obtained as part of a calibration process of the 3D printing system or as part of an operational process of the 3D printing system.

Abstract: Complexity of a geometry of a desired (i.e., target) three-dimensional (3D) object being produced by an additive manufacturing system, as well as atypical behavior of the processes employed by such a system, pose challenges for producing a final version of the desired 3D object with fidelity relative to the desired object. An example embodiment enables such challenges to be overcome as a function of feedback to enable the final version to be produced with fidelity. The feedback may be at least one value that is associated with at least one characteristic of a printed object following processing of the printed object. Such feedback may be obtained as part of a calibration process of the 3D printing system or as part of an operational process of the 3D printing system.

Abstract: A camera assembly is employed in additive manufacturing to improve the fidelity of a printed object. The camera may scan the surface of a build plate of a 3D printer and an object as it is being printed to generate image data. The image data is processed to detect errors in the build plate or printed object. The printer compensates for the detected errors, which can including modifying the printer configuration and/or modifying the instructions for printing a given object. Using the updated configuration, subsequent objects may then be printed, under a corrected process, to produce an object with fidelity to an original object model.

Abstract: A variety of additive manufacturing techniques can be adapted to fabricate a substantially net shape object from a computerized model using materials that can be debound and sintered into a fully dense metallic part or the like. However, during sintering, the net shape will shrink as binder escapes and the base material fuses into a dense final part. If the foundation beneath the object does not shrink in a corresponding fashion, the resulting stresses throughout the object can lead to fracturing, warping or other physical damage to the object resulting in a failed fabrication. To address this issue, a variety of techniques are disclosed for substrates and build plates that contract in a manner complementary to the object during debinding and sintering.

Abstract: A system and corresponding method to move build material in a three-dimensional (3D) printing system uses a gripper. The gripper is arranged to apply at least two opposing lateral forces to the build material. The at least two opposing lateral forces are applied to the build material, in conjunction with linear motion of the gripper, for at least a portion of a path the build material travels toward an extrusion head.

Abstract: A debinder provides for debinding printed green parts in an additive manufacturing system. The debinder can include a storage chamber, a process chamber, a distill chamber, a waste chamber, and a condenser. The storage chamber stores a liquid solvent for debinding the green part. The process chamber debinds the green part using a volume of the liquid solvent transferred from the storage chamber. The distill chamber collects a solution drained from the process chamber and produces a solvent vapor from the solution. The condenser condenses the solvent vapor to the liquid solvent and transfer the liquid solvent to the storage chamber. The waste chamber collects a waste component of the solution.

Abstract: A system for separating objects within a stacked powder print bed of nested objects comprises a build box configured to contain the powder print bed. The build box has a build box top and a build box floor. The system further includes an elongated aperture formed in a side wall of the build box, and a de-powdering subsystem configured to mechanically and electrically engage the build box. A separating blade associated with the de-powdering subsystem is configured to be inserted through the elongated aperture and into the powder print bed between a top-most print bed layer of the nested objects and a second print bed layer directly below and contiguous with the top-most layer, thereby forming an isolated powder print bed between the separating blade and the build box top. The unbound powder may be agitated by various techniques and subsequently removed from the objects.

Abstract: A system and corresponding method to move build material in a three-dimensional (3D) printing system uses a gripper. The gripper is arranged to apply at least two opposing lateral forces to the build material. The at least two opposing lateral forces are applied to the build material, in conjunction with linear motion of the gripper, for at least a portion of a path the build material travels toward an extrusion head.

Abstract: A de-powdering basket comprises an enclosure of at least one side wall and a bottom wall. The enclosure is configured such that, when the enclosure is disposed within a build box, the outer surfaces of the at least one side wall are substantially adjacent to the interior walls of the build box. The enclosure further comprises one or more apertures disposed within the at least one side wall, each of the apertures comprising a void that extends through the at least one side wall from an interior surface of the side wall to an exterior surface of the side wall. The enclosure may be configured to accommodate a build plate situated within the enclosure. Outer edges of the build plate may cooperate with inner surfaces of the side walls of the enclosure to prevent loose powder from passing between the outer edges of the build plate and the side walls.

Abstract: Support structures are used in certain additive fabrication processes to permit fabrication of a greater range of object geometries. For additive fabrication processes with materials that are subsequently sintered into a final part, an interface layer is fabricated between the object and support in order to inhibit bonding between adjacent surfaces of the support structure and the object during sintering. Interface layers suitable for manufacture with an additive manufacturing system may resist the formation of bonds between a support structure and an object during subsequent sintering processes.

Abstract: Mold lock is remediated by performing a layer-by-layer, two-dimensional analysis to identify unconstrained removal paths for any support structure or material within each two-dimensional layer, and then ensuring that aligned draw paths are present for all adjacent layers, all as more specifically described herein. Where locking conditions are identified, a sequence of modification rules are then applied, such as by breaking support structures into multiple, independently removable pieces. By addressing mold lock as a series of interrelated two-dimensional geometric problems, and reserving three-dimensional remediation strategies for more challenging, complex mold lock conditions, substantial advantages can accrue in terms of computational speed and efficiency.

Abstract: In an aspect, multiple metallic base materials are mixed into a user-controlled multimetallic mixture and extruded into a net shape, which is thermally processed into a multimetallic and/or alloyed object. In another aspect, a superstructure is fabricated around an object, but physically isolated from the object, with a shape facilitating robotic handling of the superstructure, along with removal of powder from the object, after a three-dimensional printing process. In another aspect, a ceramic precursor is used to create a separable interface between a support structure and a sinterable object. More specifically, a sinterable structure is fabricated from a sinterable powder in an aqueous binder, and an interface layer is formed by depositing a ceramic precursor in a nonaqueous solution onto the sinterable structure. When the ceramic precursor is exposed to water in the aqueous binder, the ceramic can precipitate to form an unsinterable, ceramic interface layer between sinterable structures.

Abstract: Support structures are used in certain additive fabrication processes to permit fabrication of a greater range of object geometries. For additive fabrication processes with materials that are subsequently sintered into a final part, an interface layer is formed between the object and support in order to inhibit bonding between adjacent surfaces of the support structure and the object during sintering. The support structure may be a multi-part support structure to mitigate mold lock or facilitate removal from enclosed spaces.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process. The shape of an extrusion nozzle may be varied during extrusion to control, e.g., an amount of build material deposited, a shape of extrudate exiting the nozzle, a feature resolution, and the like.

Abstract: Devices, systems, and methods are directed to applying magnetohydrodynamic forces to liquid metal to eject liquid metal along a controlled pattern, such as a controlled three-dimensional pattern as part of additive manufacturing of an object. The magnetohydrodynamic force can be pulsed to eject droplets of the liquid metal to provide control over accuracy of the object being fabricated. The pulsations can be applied in fluid chambers having high resonance frequencies such that droplet ejection can be effectively controlled over a wide range of frequencies, including high frequencies suitable for liquid metal ejection at rates suitable for commercially viable three-dimensional fabrication.