Abstract: A method and system for a three dimensional printing system are described herein. In one example, the three dimensional printing system has a moveable carriage, an array of laser modules and a print controller. In this example, the moveable carriage has a print head arranged to selectively deposit a printing agent on to a layer of build material as the moveable carriage is moved relative to the layer of build material. The printing agent controls localized fusing of the build material on application of energy. The print controller is communicatively coupled to the array of laser modules and controls activation of individual laser modules of the array of laser modules so as to apply, selectively, energy to addressable sub-regions of the layer of build material on which printing agent has been deposited to control fusing together with the deposited printing agent.

Abstract: In one example a system is for post-processing a three-dimensional (3D) object generated in an additive manufacturing process in which an identifiable agent is applied to a portion of a build material to form a portion of the 3D object. The system comprises an identification unit and a sensor. The identification unit is to cause the identifiable agent to become distinguishable to thereby cause the portion of the 3D object, corresponding to the portion of build material to which the identifiable agent was applied, to be distinguishable from any build material remnant disposed on the 3D object and to which no identifiable agent was applied. The sensor is to distinguish the build material remnant from the portion of the 3D object.

Abstract: According to one example there is provided a method for three-dimensional printing. The method comprises forming a pile of build material on a heatable plate adjacent a spreader, heating the pile of build material by contact with the heatable plate, and spreading the heated pile of build material on a support platform.

Abstract: A method and system for a three dimensional printing system are described herein. In one example, the three dimensional printing system has a moveable carriage, an array of laser modules and a print controller. In this example, the moveable carriage has a print head arranged to selectively deposit a printing agent on to a layer of build material as the moveable carriage is moved relative to the layer of build material. The printing agent controls localized fusing of the build material on application of energy. The print controller is communicatively coupled to the array of laser modules and controls activation of individual laser modules of the array of laser modules so as to apply, selectively, energy to addressable sub-regions of the layer of build material on which printing agent has been deposited to control fusing together with the deposited printing agent.

Abstract: A printing unit comprises a movable carriage being movable along a path and having a plurality of energy emitters arranged in an array, a controller to control a supplied energy level of the emitters, and a sensor unit to measure an emitted energy level of each emitter, wherein the controller is to compare the measured energy level with a target energy level associated with the supplied energy level to obtain and to generate a matrix indicating a compensation value for each emitter based on the comparison result so as to calibrate the energy level of comparison result.

Abstract: According to one example, there is provided a method of controlling a three-dimensional printing system, comprising obtaining data relating to a three-dimensional object to be generated, controlling a set of process modules to move around a path in a single direction over a build chamber to selectively perform a respective process action on the build platform to generate a three-dimensional object therein.

Abstract: There is disclosed additive manufacturing apparatus (10), (22), (34) comprising: a heater (18), (36) to direct radiant heat onto an irradiation region (20) of a build platform (12), at least part of the heater (18), (36) being moveable to cause the irradiation region (20) to traverse over the build platform (12); a coating module (14) moveable relative the heater (18), (36) to traverse the build platform (12) to apply a build material onto the build platform (12); and a print module (16) moveable relative the heater (18), (36) to traverse the build platform (12) to selectively eject a print agent onto the build material.

Abstract: In example implementations, an apparatus includes a storage unit, an auger screw, a housing enclosing the auger screw and at least one heater coupled to the housing. The auger screw receives a build material from the storage unit and delivers the build material to a build platform via movement of the auger screw. The build material is heated by the at least one heater as the build material is being moved by the auger screw.

Abstract: In an example, a method includes acquiring a thermal image of a reflector within an additive manufacturing apparatus through a screen. An energy profile of the thermal image of the reflector may be determined and, based on the energy profile, an operational characteristic of the screen may be determined.

Abstract: In an example, an air filtration apparatus includes a cyclonic particle separation chamber having a first inlet to draw air from a first region, second inlet to draw air from a second region, and an exhaust port. The air filtration apparatus may further include a pressure sensor to sense a pressure of the first region, and a cyclonic air flow controller. The cyclonic air flow controller may control an air inflow received via the second inlet in response to an output from the pressure sensor to maintain a total air flow rate via the exhaust port.

Abstract: In example implementations, an apparatus includes a storage unit, an auger screw, a housing enclosing the auger screw and at least one heater coupled to the housing. The augers screw receives a build material from the storage unit and delivers the build material to a build platform via movement of the auger screw. The build material is heated by the at least one heater as the build material is being moved by the auger screw.

Abstract: Mechanisms to spread build material on a print bed are disclosed. In example apparatuses a conveyor, having an endless belt, is used. A build material reservoir deposits build material on the endless belt, in a build material receiving area of the conveyor. A build material preheater is used to preheat build material transported by the endless belt in a build material preheating area of the conveyor. The preheated build material is then deposited on the print bed.

Abstract: A printing system to hold printing material comprises a sealing interface to seal a container with respect to a printing chamber volume of the printing system, the container to hold the printing material. The printing system comprises a lifting system to move the container between a first position in which the container is to be lifted and a second position at which the container is lifted and contacts the seal so as to seal the container. The lifting system is to non-hyperstatically constrain the container.

Abstract: In one example In accordance with the present disclosure, a fluid ejection device is described. The fluid ejection device Includes a number of nozzles to eject fluid. Each nozzle Includes multiple firing chambers to hold fluid. The multiple firing chambers are separated: by a chamber partition. Each nozzle also includes a shared nozzle orifice in a substrate through which to dispense fluid. Each nozzle also Includes multiple ejectors, at least one ejector disposed in each firing chamber, in a common channel of the nozzle, fluid from the multiple firing chambers Is mixed, A height of the common channel is defined by the substrate and the chamber partition and is less than a width of the shared nozzle orifice.

Abstract: A method and system for a three dimensional printing system are described herein. In one example, the three dimensional printing system has a moveable carriage, an array of laser modules and a print controller. In this example, the moveable carriage has a print head arranged to selectively deposit a printing agent on to a layer of build material as the moveable carriage is moved relative to the layer of build material. The printing agent controls localized fusing of the build material on application of energy. The print controller is communicatively coupled to the array of laser modules and controls activation of individual laser modules of the array of laser modules so as to apply, selectively, energy to addressable sub-regions of the layer of build material on which printing agent has been deposited to control fusing together with the deposited printing agent.

Abstract: A printer is disclosed. The printer comprises a resistive load and a control system. The control system is to control the resistive load. The control system is to determine a resistance value of the resistive load. The control system is to determine a voltage transition mode for transitioning the voltage applied across the resistive load to a target voltage value depending on the resistance value. The control system is to transition the voltage applied across the resistive load to the target voltage value according to the determined voltage transition mode.

Abstract: According to one example, there is provided apparatus for generating a three-dimensional object. The apparatus comprises a build material distributor movable bi-directionally in a first axis to deposit successive layers of a build material on a support, and an agent distributor movable bi-directionally in a second axis different to the first axis to deliver an agent onto selected portions of successive layers of build material.

Abstract: A removable build module to connect to a host apparatus, may include a build platform to support an object-to-be-built, a drive unit to move the build platform, a memory to receive and store build parameters, and an interface circuit to communicate the build parameters to the host apparatus.

Abstract: In one example, an additive manufacturing system. An unsealed air supply enclosure for clean air is maintained at a first pressure above an ambient air pressure to inhibit unfiltered ambient air from leaking into the enclosure. An unsealed processing chamber is maintained at a second pressure below the ambient air pressure to inhibit processing chamber air from leaking out of the processing chamber. An air pathway is disposed between the air supply enclosure and the processing chamber to provide clean air from the air supply enclosure to the processing chamber.

Abstract: A transport device (106) includes a first volume (110) to receive a build material and a second volume (108) to contain an object created by an additive manufacturing system (100). The transport device (106) is receivable by a 3D printer (102) of the additive manufacturing system, and the 3D printer to build the object in the second volume. The transport device (106) is receivable by an extracting and supply device (104). The extracting and supply device is to extract the object from the second volume and to supply the build material to the first volume.