Abstract: A three-dimensional object printer includes at least one ejector that is operated to form an uppermost layer of photopolymer material on a substrate. The ejected uppermost photopolymer layer is partially cured and a portion of mesh sheet is positioned on the partially cured layer before the at least one eject continues to eject photopolymer material onto the uppermost layer. The portion of the mesh sheet reinforces the layers of photopolymer material and adds strength and durability to the overall part being formed with the photopolymer material.

Abstract: A method of printing an internal bridge in a three-dimensional object includes depositing a plurality of drops of a printing material in a first direction to form a supported stepout onto an edge of a bridging layer, depositing a plurality of drops of the printing material to form an anchor layer adjacent to and in contact with a supported stepout, and depositing a plurality of drops of the printing material to form an unsupported stepout adjacent to an in contact with the supported stepout. A printing system for three-dimensional objects is also described, which is configured to perform the method of printing an internal bridge in a three-dimensional object.

Abstract: A method of operating a printer to fill an internal volume of a three-dimensional object is includes determining a total number of layers required to fill an internal volume of a three-dimensional object, forming at least one floor layer within the internal volume, using a maximum individual stepout distance to generate machine-ready instructions that operate the printer to form one or more pre-determined sloped edges of a plurality of sections of a sparse infill structure in the layer of the internal volume to be filled, thereby forming at least one sparse infill layer. A drop ejecting apparatus includes a controller operatively connected to a reservoir, an ejector, and at least one actuator, the controller being configured to perform the method as described herein.

Abstract: A method of operating a three-dimensional (3D) metal object manufacturing apparatus selects operational parameters for operation of the printer to form conductive metal traces on substrates with dimensions within appropriate tolerances and with sufficient conductive material to carry electrical currents without burning up or becoming too hot. The method identifies the material of the substrate and the bulk metal being melted for ejection and uses this identification data to select the operational parameters. Thus, the method can form conductive traces and circuits on a wide range of substrate materials including polymeric substrates, semiconductor materials, oxide layers on semiconductor materials, glass, and other crystalline materials.

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 of operating a three-dimensional (3D) metal object manufacturing apparatus selects operational parameters for operation of the printer to form conductive metal traces on substrates with dimensions within appropriate tolerances and with sufficient conductive material to carry electrical currents without burning up or becoming too hot. The method identifies the material of the substrate and the bulk metal being melted for ejection and uses this identification data to select the operational parameters. Thus, the method can form conductive traces and circuits on a wide range of substrate materials including polymeric substrates, semiconductor materials, oxide layers on semiconductor materials, glass, and other crystalline materials.

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: Systems for and methods of providing a feed rate for three-dimensional printing a part are presented. The disclosed techniques include: obtaining computer readable toolpath instructions for the part, where the toolpath instructions specify a nominal feed rate for a toolpath segment and spatial toolpath data of the toolpath segment; providing an input including the spatial toolpath data to a trained machine learning system, where the trained machine learning system has been trained using training data including: training spatial toolpath data, training closed loop gain data, and training feed rate data; obtaining a revised feed rate for the toolpath segment different from the nominal feed rate for the toolpath segment, where the revised feed rate is output from the trained machine learning system; and providing revised computer readable toolpath instructions, where the revised machine learning toolpath instructions include the revised feed rate.

Abstract: A slicer in a material drop ejecting three-dimensional (3D) object printer identifies the positions and local densities for a plurality of infill lines within a perimeter to be formed within a layer of an object to be formed by the printer. The local density of each infill line is filtered and a control law is applied to the filtered local density to identify an error in the local density compared to a target density. This process is performed iteratively until the error is within a predetermined tolerance range about the target local density. The error is used to generate machine ready instructions to operate the 3D object printer to achieve the target density for the infill lines.

Abstract: A method includes ejecting a plurality of drops of a build material from a nozzle of a 3D printer. The build material cools and solidifies after being ejected to form a 3D object. The method also includes controlling an oxidation of the drops, the 3D object or both to create different oxidation levels in first and second portions of the 3D object.

Abstract: A metal object manufacturing apparatus is configured to eject melted metal drops to form a continuous metal line over a line of spatially separated pillars in a single pass. The ejection frequency for forming the continuous metal line is different than the frequency used to form the pillars. In one embodiment, the ejection frequency for forming the pillars is about 100 Hz and the frequency used to form the continuous metal line over the line of spatially separated pillars is about 300 Hz with a drop spacing of about 0.2 mm. Continuous metal lines are formed to extend the continuous metal lines over the pillars laterally to fill the gaps between the continuous metal lines over the pillars. These continuous metal lines that fill the gaps are formed while operating the ejection head at the 300 Hz frequency with a drop spacing of 0.28 mm.

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 method of operating a multi-nozzle extruder in an additive manufacturing system enables support structure to be formed while an object is also being formed. The method includes opening more than one nozzle in the multi-nozzle extruder, and operating an actuator with a controller to move the multi-nozzle extruder along a path to form a first group of multiple parallel ribbons of support structure simultaneously with material extruded from the more than one open nozzle.

Abstract: A slicer in a material drop ejecting three-dimensional (3D) object printer determines the number of material drops to eject to form a perimeter in an object layer and distributes a quantization error over the layers forming the perimeter. The slicer also identifies the location for the first material drop ejected to form the perimeter using a blue noise generator.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus is operated to form sloping surfaces having a slope angle of more than 45° from a line that is perpendicular to the structure on which the layer forming the slope surface is formed. The angle corresponds to a step-out distance from the perpendicular line and a maximum individual step-out distance determined from empirically derived data. Multiple passes of an ejection head of the apparatus can be performed within a layer to form a sloped edge and the mass of the sloped structure is distributed within the sloped edge so the edge is formed without defects.

Abstract: A method of operating a three-dimensional (3D) metal object manufacturing apparatus selects operational parameters for operation of the printer to form conductive metal traces on substrates with dimensions within appropriate tolerances and with sufficient conductive material to carry electrical currents without burning up or becoming too hot. The method identifies the material of the substrate and the bulk metal being melted for ejection and uses this identification data to select the operational parameters. Thus, the method can form conductive traces and circuits on a wide range of substrate materials including polymeric substrates, semiconductor materials, oxide layers on semiconductor materials, glass, and other crystalline materials.

Abstract: A three-dimensional (3D) object printer operates a radiation source to direct radiation emitted by the radiation source through a porous substrate at a first intensity insufficient to cure a material contained in the porous substrate and at a second intensity sufficient to cure the material after the emitted radiation has passed through the porous substrate. The material is applied to the porous substrate by one or more wipers.

Abstract: A metal object manufacturing apparatus is configured to eject melted metal drops to form a continuous metal line over a line of spatially separated pillars in a single pass. The ejection frequency for forming the continuous metal line is different than the frequency used to form the pillars. In one embodiment, the ejection frequency for forming the pillars is about 100 Hz and the frequency used to form the continuous metal line over the line of spatially separated pillars is about 300 Hz with a drop spacing of about 0.2 mm. Continuous metal lines are formed to extend the continuous metal lines over the pillars laterally to fill the gaps between the continuous metal lines over the pillars. These continuous metal lines that fill the gaps are formed while operating the ejection head at the 300 Hz frequency with a drop spacing of 0.28 mm.

Abstract: A three-dimensional (3D) metal object manufacturing apparatus selects operational parameters for operation of the printer to form conductive metal traces on substrates with dimensions within appropriate tolerances and with sufficient conductive material to carry electrical currents without burning up or becoming too hot. The apparatus identifies the material of the substrate and the bulk metal being melted for ejection and uses this identification data to select the operational parameters. Thus, the apparatus can form conductive traces and circuits on a wide range of substrate materials including polymeric substrates, semiconductor materials, oxide layers on semiconductor materials, glass, and other crystalline materials.

Abstract: A slicer in a material drop ejecting three-dimensional (3D) object printer identifies the positions and local densities for a plurality of infill lines within a perimeter to be formed within a layer of an object to be formed by the printer. The local density of each infill line is filtered and a control law is applied to the filtered local density to identify an error in the local density compared to a target density. This process is performed iteratively until the error is within a predetermined tolerance range about the target local density. The error is used to generate machine ready instructions to operate the 3D object printer to achieve the target density for the infill lines.