Abstract: Some examples include a fusing apparatus for an additive manufacturing machine. The fusing apparatus includes an enclosure movable in an x-direction across the build zone, the build zone is to contain a build material and a fusing agent. A thermic source is housed in the enclosure, the thermic source is to direct thermic energy toward the build zone and includes a warming source to emit a first emission spectrum and a fusing source to emit a second emission spectrum. A control is to continuously modulate levels of the thermal energy produced by the thermic source during a build cycle.

Abstract: Example systems relate to reflective barriers. In some examples, devices utilizing reflective barriers can include a carriage device, comprising an enclosure to encase a plurality of energy sources directed in a particular direction, and a reflective barrier positioned within the enclosure, wherein the reflective barrier comprises a reflective insulation material.

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: In one example, a fusing system for an additive manufacturing machine includes a first carriage carrying a layering device and a fusing lamp, and a second carriage carrying a fusing agent dispenser. The first carriage and the second carriage are movable back and forth over the work area along the same line of motion so that the first carriage follows the second carriage in one direction and the second carriage follows the first carriage in the other direction.

Abstract: Some examples include a thermal imaging assembly, comprising a thermal imaging device including a thermal sensor, a transistor to generate heat, a thermal jacket forming a cavity to house the thermal imaging device, the thermal jacket forming a space around the thermal imaging device, the thermal jacket thermally coupled to the transistor to transmit heat generated by the transistor to the cavity, and an insulative shell disposed around the thermal jacket to maintain a temperature of the thermal imaging device within the insulative shell.

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: A power control system enables an electrical apparatus to intermittently operate at power levels which exceed an available facility power. The power control system draws a sufficiently high current from a power source (e.g., mains supply) to supply power to components of the apparatus that generate a continuous below-threshold load, while at the same time, supplying a charge current for a battery module. The power control system can operate to use the battery module to supply power to components of the apparatus that draw excess power when the electrical apparatus operates at an above-threshold power level.

Abstract: A method for fabricating three dimensional objects herein can include calibrating a system to detect a temperature component and a current component by operating a heating source with at least two different calibration voltages and monitoring a color temperature of the heating source and an optical power of the heating source at each of the at least two different calibration voltages. The method can also include performing a three dimensional printing operation while applying a fabrication voltage to the heating source and monitoring the fabrication voltage and a current of the heating source during the three dimensional printing operation. Furthermore, the method can include adjusting the fabrication voltage of the heating source in response to a change in a resistance of the heating source or a characteristic of the three dimensional object, wherein the fabrication voltage is adjusted based at least on the temperature component and the current component.

Abstract: An example system includes an imaging device and an enclosure substantially separating the imaging device from an outside environment. The enclosure includes an air intake to force air into the enclosure and an aperture to allow air to escape the enclosure. The air intake and the aperture maintain an air pressure level in the enclosure greater than an air pressure of the outside environment.

Abstract: According to an example, an apparatus may include a recoater, an energy source, a carriage supporting the energy source, and a controller. The controller may control the recoater to spread build material particles into a layer on top of a previously applied layer containing fused build material particles and the carriage to move ahead of the recoater to cause the energy source to apply energy onto build material particles in the previously applied layer prior to the recoater spreading the build material particles onto the previously applied layer. The energy source is to heat the fused build material particles to or maintain the fused build material particles at a temperature above a certain temperature and the recoater is to be controlled to spread the build material particles on top of the previously applied layer prior to the fused build material particles falling below the certain temperature.

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: 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: In an example implementation, a method of fusing layers of 3D parts includes forming a layer of build material, and selectively applying a liquid agent onto the layer of build material to define a part layer of a 3D part and a sacrificial layer of a sacrificial part. The method includes, in a single pass of a thermal energy source over the layer of build material, applying fusing energy to the sacrificial layer, sensing a temperature of the sacrificial layer, adjusting a power level of the thermal energy source based on the sensed temperature, and applying fusing energy to the part layer with the adjusted power level of the thermal energy source.

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 fusing system for an additive manufacturing machine includes a first carriage carrying a layering device and a fusing lamp, and a second carriage carrying a fusing agent dispenser. The first carriage and the second carriage are movable back and forth over the work area along the same line of motion so that the first carriage follows the second carriage in one direction and the second carriage follows the first carriage in the other direction.

Abstract: A reflector assembly for an additive manufacturing apparatus comprises a first reflector comprising a first reflector section having a first reflecting surface and a second reflector comprising a second reflector section having a second reflecting surface. The first reflector section is for reflecting radiation from a first radiating element located, in use, proximate to the first reflecting surface, and the second reflector section is for reflecting radiation from a second radiating element located, in use, proximate to the second reflecting surface. The first reflector section and the second reflector section are each formed of a ceramic material.

Abstract: In one example, a fusing system for an additive manufacturing machine includes a warmer to preheat unfused build material in a work area, a dispenser to dispense a fusing agent on to build material in the work area in a pattern corresponding to an object slice, a fusing lamp to fuse patterned build material in the work area, a temperature sensor to measure a temperature of preheated unfused build material in the work area, and a controller operatively connected to the warmer and to the temperature sensor to adjust a heat output of the warmer to the work area based on a temperature measured by the temperature sensor.

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.