Abstract: In an example, a method includes in an additive manufacturing process, generating a first object and generating an ancillary object on top of the first object to reduce a thermal gradient of the first object during cooling.

Abstract: In one example, a decaking system for 3D printing includes a platform to support multiple green parts in unbound powder surrounding the green parts, a decaking tool to remove unbound powder from around the green parts, a camera to photograph green parts on the platform as unbound powder is removed from around the green parts, and a controller operatively connected to the camera. The controller is programmed to detect a pattern of light intensity in the photographs and, in response to a determination a detected pattern matches a reference pattern, modulate or stop the decaking tool.

Abstract: In an example, a method includes receiving, by at least one processor, object model data, the object model data describing at least part of an object to be generated in additive manufacturing. Pattern data is also received, wherein the pattern data describes a pattern of variable opacity intended to be formed internally to the object. Object generation instructions for generating an intermediate layer of the object comprising the pattern of variable opacity may be determined by at least one processor.

Abstract: A method comprising dividing a build model comprising an object model arranged within a virtual volume into cross-sectional layers along a vertical axis. The layers represent layers of an additive manufacturing process. A set of base layers is identified with each of the base layers comprising a flat bottom surface of the object model. A base characteristic is assigned to the set of base layers. A set of bulk layers is identified which excludes the set of base layers. A bulk characteristic is assigned to the set of bulk layers. An additive manufacturing apparatus is instructed to build a build cake according to the build model, layers and assigned characteristics, so a fluid agent is deposited at a first rate for the set of bulk layers having the bulk characteristic and a second rate, slower than the first rate, for the set of base layers having the base characteristic.

Abstract: A mask is described comprising a mask body for covering the nose and mouth of a wearer, and a cushion for sealing against the wearer's face. The cushion depends inwardly from the periphery of the mask body. The mask body and the cushion are formed of an elastomeric material, and the mask body is shaped such that, when the mask is worn by the wearer, the mask body flexes about a median plane.

Abstract: A 3D printer is disclosed herein. The 3D printer comprises a build material distributor, an agent delivery device and a controller. The controller obtains slice image data of a sliced virtual build volume including a 3D object to be generated, where the slice image data is indicative, for each slice, of the portions of corresponding build material layers to be solidified. The controller is to determine print data corresponding to each slice, the print data defining a density of printing agent to be applied to regions of each layer based on the slice image data; and to obtain additional data relating to a portion of a slice that corresponds to a sloped portion of the 3D object. The controller is further to modify the determined print data to modify the density of printing agent to be printed at a portion of a given build material layer based on the additional data.

Abstract: A computer-implemented method is disclosed. The method comprises receiving object data relating to a three-dimensional object generated or to be generated using an additive manufacturing apparatus, the object data including details of an aperture in a surface of the three-dimensional object; determining, based on the object data, design data for a jig to engage the object and to form a fluid communication channel between the aperture in the surface of the three-dimensional object and an interface of an airflow control mechanism, the airflow control mechanism to cause a flow of air through the aperture; and providing the design data for delivery to an additive manufacturing apparatus to generate the jig. A jig is also disclosed.

Abstract: A method of adjusting a three-dimensional representation of an object to be manufactured in an additive manufacturing process comprises determining a processing operation to be applied to the object, and adjusting the three-dimensional representation of the object based on adjustment parameters associated with the processing operation.

Abstract: In one example, a decaking system for 3D printing includes a platform to support multiple green parts in unbound powder surrounding the green parts, a decaking tool to remove unbound powder from around the green parts, a camera to photograph green parts on the platform as unbound powder is removed from around the green parts, and a controller operatively connected to the camera. The controller is programmed to detect a pattern of light intensity in the photographs and, in response to a determination a detected pattern matches a reference pattern, modulate or stop the decaking tool.

Abstract: Examples of a method of operating an additive manufacturing system, a three-dimensional (3D) printing system and a non-transitory machine-readable medium are described. In an example, a build material is supplied to a print region of an additive manufacturing system. A temperature distribution, corresponding to a pattern, of at least a surface of the build material is generated. An image of the pattern is captured using a thermal sensor. Image data representative of the image of the pattern is compared with data representative of an expected position of the pattern. On the basis of the comparing, difference data indicative of a difference between a position of the thermal sensor during capture of the image and an expected position of the thermal sensor associated with the expected position of the pattern is generated. Operation of the additive manufacturing system is controlled at least in dependence on the difference data.

Abstract: In one example, a system for loading a build material powder supply receptacle for a 3D printer includes a reconditioner having a container and a heater to burn unwanted residue from used build material powder in the container, to form reconditioned build material powder, a conveyor operatively connected to the reconditioner to convey used build material powder to the container, and a dispenser operatively connected to the reconditioner to dispense reconditioned build material powder from the container into the supply receptacle.

Abstract: According to one example, there is provided a 3D printing build unit comprising a build chamber, a build platform, and a heating element controllable to heat a portion of the contents of the build chamber to a temperature at or above a curing temperature whilst maintaining upper layers of the build chamber at or below a printing temperature.

Abstract: According to one aspect there is provided a three-dimensional printer. The printer comprises a controller to obtain data relating to a layer of a build model, to process non-empty layers according to a first operating mode and to process empty layers according to a second operating mode.

Abstract: A controller-implemented method of controlling a three dimensional (3D) printing process, comprises presenting printing options (20) of the 3D printing process at a user interface (16); accepting settings (22) from the user interface (16) based on the presented printing options (20); determining a printing instruction (24) based on the settings (22), the printing instruction (24) to be used to manufacture a three-dimensional (3D) object; and determining a post-processing instruction (26) based on the settings (22), the post-processing instruction (26) to be used in post-processing the 3D object.

Abstract: A method is disclosed. The method may comprise obtaining, using a processor, design data representing an object to be generated in a fabrication chamber of an additive manufacturing apparatus. The method may further comprise determining, based on the design data, that a part of the object is to be generated within a predefined portion of the fabrication chamber. The method may further comprise responsive to said determining, generating, using a processor, data representing an ancillary element to be generated in the predefined portion between the part of the object and a wall of the fabrication chamber. An apparatus and a machine-readable medium are also disclosed.

Abstract: According to an example, a computing apparatus may include a processing device and a machine readable storage medium on which is stored instructions that when executed by the processing device, cause the processing device to access, from a sensing device, information pertaining to formation of a part of a 3D object in a layer of build materials upon which fusing agent droplets have been or are to be selectively deposited. The instructions may also cause the processing device to predict, based upon the accessed information, a quality of the part and output an indication of the predicted quality of the part.

Abstract: A method comprises receiving data representing a 3D object model. The 3D object model is for use in generating a 3D object in a build chamber by forming a plurality of successive layers. Each layer is formed by providing a layer of build material and applying a volume of a binder agent to a plurality of voxel locations of the layer of the build material. The volume of the binder agent to be applied to each voxel location is based on the volume of binder agent to be applied to proximate voxel locations of the 3D object.

Abstract: Certain examples described herein relate to preparing a base of build material for additive manufacturing. The base is formed from layers of build material that do not form part of an object undergoing additive manufacture. The base is heated by the application of energy, for example using a radiation source. A thermal profile of the base is measured after heating and is used to determine a pattern of application of at least one printing agent to the base. The pattern of application is used to deposit the at least one printing agent upon the base, wherein the presence of the printing agent affects the heating of the base. In this way the pattern of application of printing agent may be used to effect a thermal homogeneity of the base.

Abstract: Apparatus, computer readable medium, or method to determine a layer volume change in a processed layer of powder, and distribute an additional amount of powder in a subsequent layer based on the determined layer volume change.

Abstract: Apparatus, computer readable medium, or method to determine a layer volume change in a processed layer of powder, and distribute an additional amount of powder in a subsequent layer based on the determined layer volume change.