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: 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 one example, an apparatus for generating a three-dimensional object includes an energy source to apply energy to a layer of build material to cause a first portion of the layer to coalesce and solidify, an agent distributor to selectively deliver a cooling agent onto a second portion of the layer, and a controller to control the energy source to apply energy to the layer to cause the first portion to coalesce and solidify in a first pattern and to control the agent distributor to selectively deliver the cooling agent onto the second portion of the layer in a second pattern independent of the first pattern.

Abstract: According to examples, a build module may include a housing, a build material chamber, and a build chamber. The build material chamber may be positioned beneath the build chamber in the housing and may include a moveable support member, in which a build material distributor is to supply successive layers of build material onto the moveable support member from the build material chamber. The build module may be removably insertable into a build receiver of an additive manufacturing system to allow the additive manufacturing system to solidify a portion of the successive layers received onto the moveable support member during the solidification process of the build material. The moveable support member may separate the build material chamber from the build chamber to block build material from the above the build material chamber from being received into the build material chamber during a solidification process of the build material.

Abstract: According to examples, a build module may include a housing, a build material chamber, and a build chamber. The build material chamber may be positioned beneath the build chamber in the housing and may include a moveable support member, in which a build material distributor is to supply successive layers of build material onto the moveable support member from the build material chamber. The build module may be removably insertable into a build receiver of an additive manufacturing system to allow the additive manufacturing system to solidify a portion of the successive layers received onto the moveable support member during the solidification process of the build material. The moveable support member may separate the build material chamber from the build chamber to block build material from the above the build material chamber from being received into the build material chamber during a solidification process of the build material.

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: 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: 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 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: 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.

Abstract: Examples of temperature measurement calibration in an additive manufacturing system are described. In one case, a method of calibrating a non-contact temperature measurement device involves applying energy from a radiation source of the additive manufacturing system to heat a reference element. The reference element is thermally coupled to a temperature sensor. A temperature reading from the temperature sensor is compared with data from the non-contact temperature measurement device to calibrate the device.

Abstract: In an example, a method includes forming a layer of build material and selectively applying fusing agent on to the layer based on a predetermined pattern. Energy may be applied to the layer of build material, and at least one temperature of the layer may be measured. A temperature distribution over the layer of build material may be determined, the temperature distribution indicating, for each of a plurality of locations on the layer of build material, whether fusing agent is present at that location. At least one characteristic derived from the temperature distribution may be compared to a predetermined characteristic. When the compared characteristics differ, an operational characteristic of an additive manufacturing apparatus may be adjusted.

Abstract: An apparatus (100) for generating three dimensional objects comprises a first scanning carriage (102). The first scanning carriage comprises a first energy source (104) to pre-heat an area of a build surface as the first scanning carriage (102) moves over the build surface.

Abstract: According to examples, a build module may include a housing, a build material chamber, and a build chamber. The build material chamber may be positioned beneath the build chamber in the housing and may include a moveable support member, in which a build material distributor is to supply successive layers of build material onto the moveable support member from the build material chamber. The build module may be removably insertable into a build receiver of an additive manufacturing system to allow the additive manufacturing system to solidify a portion of the successive layers received onto the moveable support member during the solidification process of the build material. The moveable support member may separate the build material chamber from the build chamber to block build material from the above the build material chamber from being received into the build material chamber during a solidification process of the build material.