Abstract: In one example, a fusing system for an additive manufacturing machine includes a fusing lamp to heat build material in the work area, a heat sensor to measure a heat output of the fusing lamp, and a controller operatively connected to the fusing lamp and to the heat sensor to adjust the heat output of the fusing lamp to the work area based on a heat output measured by the heat sensor.

Abstract: In an example implementation, a method of printing a three-dimensional (3D) object includes scanning a print bar in a first direction over a build platform of a 3D printer to deposit a liquid agent onto a layer of build powder. The print bar is then indexed in a second direction substantially orthogonal to the first direction before scanning the print bar back over the build platform in a third direction opposite the first direction to deposit additional liquid agent onto the layer of build powder.

Abstract: A control system for a three-dimensional printer includes an energy component interface, an agent depositing component interface, and control logic. The control logic controls the operation of an energy component through the energy component interface and an agent depositing component through the agent depositing component, in forming an output object that is specified in a print job. Additionally, in some examples, the control logic can implement a plurality of modes. Each mode, when selected modulate one or more operational parameters of a least one of the energy component or agent depositing component.

Abstract: According to examples, an apparatus may include a back panel to absorb energy and an energy emitter to supply energy onto a build material layer. The energy emitter may include an energy emitting element and an outer tube. In addition, a reflective element may be provided on a portion of the outer tube facing the back panel to direct energy away from the back panel. The apparatus may also include a transparent panel, in which energy from the energy emitter may be emitted through the transparent panel and onto the build material layer.

Abstract: In one example, a control process for an additive manufacturing machine includes displacing a platform, measuring the actual displacement of the platform, determining that the actual displacement varies from a nominal displacement, and determining an amount of an agent to be applied to build material layered on the displaced platform based on the determined variation.

Abstract: A build material dispensing device may include a material spreader to spread an amount of build material along a build platform, and at least one hopper for dispensing the build material. The at least one hopper dispenses a plurality of doses of the build material in front of the progression of the material spreader as the material spreader is moved over the build platform.

Abstract: In an example implementation, a method of printing a three-dimensional (3D) object includes scanning a print bar in a first direction over a build platform of a 3D printer to deposit a liquid agent onto a layer of build powder. The print bar is then indexed in a second direction substantially orthogonal to the first direction before scanning the print bar back over the build platform in a third direction opposite the first direction to deposit additional liquid agent onto the layer of build powder.

Abstract: A control system for a three-dimensional printer includes an energy component interface, an agent depositing component interface, and control logic. The control logic controls the operation of an energy component through the energy component interface and an agent depositing component through the agent depositing component, in forming an output object that is specified in a print job. Additionally, in some examples, the control logic can implement a plurality of modes. Each mode, when selected modulate one or more operational parameters of a least one of the energy component or agent depositing component.

Abstract: Some examples include methods of operating an additive manufacturing machine including generating thermal energy with a thermic source including a warming source and a fusing source, each of the warming and fusing sources having a major axis longitudinally extending in a y-axial direction above a build zone, the build zone to contain a build material and a fusing agent, moving the thermic source in a x-axial direction orthogonal to the y-axial direction over the build zone at a constant velocity, delivering a first substantially uniform heat flux from the warming source and a second substantially uniform heat flux from the fusing source to cause portions of the build material that the fusing agent is disposed on to form a layer of a three dimensional object, and continuously generating thermic energy from the thermic source during a build process of the three dimensional object.

Abstract: According to examples, an apparatus may include a back panel to absorb energy and an energy emitter to supply energy onto a build material layer. The energy emitter may include an energy emitting element and an outer tube. In addition, a reflective element may be provided on a portion of the outer tube facing the back panel to direct energy away from the back panel. The apparatus may also include a transparent panel, in which energy from the energy emitter may be emitted through the transparent panel and onto the build material layer.

Abstract: An apparatus may, in an example, include a build platform to receive a dose of build material and a build material spreader to spread the dose of build material over a length of the build platform wherein lateral portions of the build material spreader have a diameter smaller than a medial portion of the build material spreader.

Abstract: A build material dispensing device may include a material spreader to spread an amount of build material along a build platform, and at least one hopper for dispensing the build material. The at least one hopper dispenses a plurality of doses of the build material in front of the progression of the material spreader as the material spreader is moved over the build platform.

Abstract: Some examples include a method of operating an additive manufacturing machine including spreading a build material in a first direction across a build surface to form a layer, the layer having a thickness, decreasing a distance between a spread mechanism and the build surface, and translating the spread mechanism in a second direction opposite the first direction over the build surface to reduce the thickness of the layer.

Abstract: In an example, an apparatus is described that includes a non-resistive heat source, a thermally conductive face, and a temperature detector. The thermally conductive face has a controlled long-wave infrared emissivity and is in thermal contact with the non-resistive heat source. The temperature detector is positioned to detect a temperature of the thermally conductive face.

Abstract: A printing apparatus uses a time of flight sensor to determine distance between the sensor and a surface facing the sensor, and uses a reflectivity value to determine presence of print media in a media bin.

Abstract: In one example, a processor readable medium having instructions thereon that when executed cause a fusing system for an additive manufacturing machine to, during a first carriage pass, preheat build material in a layer of unfused build material; during the first carriage pass and/or during a second carriage pass, dispense a liquid fusing agent on to preheated unfused build material in the layer and then, during the second carriage pass, irradiate build material in the layer on which the fusing agent has been dispensed with a fusing light; and during a third carriage pass, irradiate the fused build material with the fusing light; and during a fourth carriage pass, irradiate the fused build material with the fusing light and then actively cool the fused build material.

Abstract: In some examples, a printer includes a feed mechanism to distribute a build material on a platform and a heater. The heater includes a lamp, a reflector, and a radiant energy absorbing baffle located between the lamp and the reflector. The lamp and the reflector are to direct radiant energy toward the platform, and the radiant energy is to heat the build material.

Abstract: In an example implementation, a method of forming a three-dimensional (3D) part includes spreading a layer of build material over a print bed, and heating the layer of build material during each of multiple consecutive carriage passes over the print bed to maintain printed portions of the build material above a melting temperature for the duration of the consecutive carriage passes.

Abstract: In some examples, an additive manufacturing system includes a dispensing device, an applicator, a thermal energy source, a thermal imaging device, and a controller. The controller is to cause the dispensing device to deposit a layer of build material and cause the applicator to apply the fusing agent to form an object portion and to apply the detailing agent to form a reference portion in the layer of build material. The controller is to cause the thermal energy source to heat the reference portion and to heat and fuse the object portion and cause the thermal imaging device to measure a temperature of the reference portion. The controller is to regulate a power level of the thermal energy source based on a comparison between the temperature of the reference portion and a set-point for the reference portion, which is based on a target temperature for the object portion.

Abstract: A three-dimensional (3D) part finishing system includes a submerging apparatus to receive a 3D printed part, and a liquid supply container to receive the submerging apparatus. The system further includes a controller operatively connected to the submerging apparatus. The controller is to receive or determine an input time for the 3D printed part and to control submersion of the submerging apparatus into the liquid supply container for the input time.