Abstract: A system includes a controller to receive data corresponding to an object or slices of the object to be generated by a 3D printer, wherein the 3D printer includes an array of printhead nozzles to selectively eject a print agent on a layer of build material in a build chamber having a build chamber wall, the array of printhead nozzles spanning substantially the full width of the build chamber and moveable along a length of the build chamber. The controller to generate first print data used to generate layers of the object based on the received object data, and to generate second print data used to generate layers of a sacrificial barrier located between the object and the build chamber wall, the second print data is generated such that different parts of the sacrificial barrier are generated using a different plurality of nozzles of the array of printhead nozzles.

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: According to examples, an apparatus may include a memory on which is stored instructions that when executed by a processor, cause the processor to access a digital file identifying a first plurality of parts to be fabricated in a first level of a build volume in a three-dimensional (3D) fabrication operation and a second plurality of parts to be fabricated in a second level of the build volume. The processor may also determine a first usage of a plurality of nozzles corresponding to fabrication of the first plurality of parts in the first level of the build volume and determine a modification to a property of the second plurality of parts to be fabricated in the second level of the build volume to have a second usage of the plurality of nozzles that differs from the first usage.

Abstract: In an example, a data unit includes a mounting to removably mount the data unit on a receiving portion of an additive manufacturing build material container, a data source to provide data comprising a plurality of additive manufacturing parameters and a communications interface to communicate with a reader of an additive manufacturing build material processing apparatus. The communications interface is to transmit data from the data source to the additive manufacturing build material processing apparatus.

Abstract: A non-transitory machine-readable storage medium is encoded with instructions executable by a processor. The machine-readable storage medium includes instructions to modify data representing a three-dimensional object model, the three-dimensional object model for use in generating a three-dimensional object in a build chamber. The data is modified to include a container to substantially encapsulate contents of the build chamber comprising the three-dimensional object and non-solidified build material. A wall of the container comprises heat transfer control elements to control dissipation of heat from the contents of the container.

Abstract: A method of producing a shell layer of an output item in an additive manufacturing process comprises forming a first laterally intermittent shell layer (74) and at least one subsequent laterally intermittent shell layer (76), wherein each laterally intermittent shell layer (74,76) at least partially overlaps and joins with at least one of the other laterally intermittent shell layers.

Abstract: In an example, a method of controlling an additive manufacturing apparatus to generate a three dimensional object comprises processing successive layers of build material so as to form successive layers of a three dimensional object, wherein the processing of each layer is performed within a predetermined layer processing time by a plurality of components. The method may further include selecting, by at least one processor, from a plurality of ancillary tasks, at least one ancillary task to be performed in relation to at least one component of the plurality of components. The method may further include scheduling, by at least one processor, the at least one ancillary task to be performed in relation to the at least one component within the predetermined layer processing time for a single layer or for multiple layers of the build material.

Abstract: Examples Include apparatuses and methods for generating three-dimensional objects. An example apparatus comprises an agent distributor and a wiping element disposed at a service location. The apparatus further comprises at least one airflow component disposed proximate the service location to generate airflow across the wiping element to reduce build material collection on the wiping element.

Abstract: There is disclosed a non-transitory machine readable storage medium encoded with instructions executable by a processor and comprising instructions to: receive object data corresponding to a three-dimensional object to be generated; define print data for each of a plurality of slices of the object to control a respective layer forming operation in which print agent is ejected on a layer of build material in a pattern corresponding to selective fusing of the build material, wherein the print data and the respective pattern is defined for each slice according to object a print definition procedure; and select the print definition procedure from a plurality of print definition procedures based on a user input. There is also disclosed a corresponding method and additive manufacturing apparatus.

Abstract: Object model data is obtained, defining an object to be generated by a three-dimensional printer. An envelope is obtained within which the object is to be generated, the envelope having a main section and at least one of a base and/or a lid, and printer control data is generated comprising build data to control a three-dimensional printer to generate the object and the envelope and a build mode data, wherein the printer control data comprises instructions to cause a three-dimensional printer to generate a build layer of the base and/or lid of the envelope using a first build mode, and to generate the object using a second build mode. The first build mode uses an extended time-per-build-layer for the generating of the build layer of the base and/or lid of the envelope compared with the second build mode.

Abstract: Examples are described that generate control data for production of a three-dimensional object. Build material profile data is accessed for an indicated build material. The build material profile data for a given build material defines one or more parameter values that are dependent on the properties of the given build material and that are configured to generate a three-dimensional object with predefined build properties.

Abstract: A system includes a controller to receive data corresponding to an object or slices of the object to be generated by a 3D printer, wherein the 3D printer includes an array of printhead nozzles to selectively eject a print agent on a layer of build material in a build chamber having a build chamber wall, the array of printhead nozzles spanning substantially the full width of the build chamber and moveable along a length of the build chamber. The controller to generate first print data used to generate layers of the object based on the received object data, and to generate second print data used to generate layers of a sacrificial barrier located between the object and the build chamber wall, the second print data is generated such that different parts of the sacrificial barrier are generated using a different plurality of nozzles of the array of printhead nozzles.

Abstract: In an example, a method includes analysing, using at least one processor, object model data representing at least a portion of an object to be generated by an additive manufacturing apparatus by fusing a build material to determine at least one predicted object generation temperature. The method may further include identifying, using at least one processor and from said analysing, a feature of the at least a portion of the object associated with a predicted object generation temperature which is below a fusing temperature of build material to be used in object generation. The method may further include determining, using at least one processor, modification data to be used in object generation, the modification data being to increase a temperature of the feature in object generation.

Abstract: In an example, a data unit includes a data unit mounting having a circuitry region, a registration portion, and a retaining feature. Circuitry comprising a data source to provide at least one additive manufacturing parameter is arranged on the circuitry region of the mounting. The data unit mounting is to be removably mounted on a receiving portion of an additive manufacturing build material component, such that the registration portion is to be received in a corresponding guide portion of the receiving portion of the additive manufacturing build material component, and the retaining feature is prevent removal of the data unit from the receiving portion unless deformed. Deformation of the retaining feature to effect removal of the data unit from the receiving portion may be a permanent deformation.

Abstract: Apparatus (100) for generating a three-dimensional object comprising a support (101) to receive build material, and a calibration platform (103) to receive a print media for use with a calibration operation performed by the apparatus. The calibration platform (103) may be moveable between a non-calibration position when the apparatus is operating in a building mode of operation, and a calibration position when the apparatus is operating in a calibration mode of operation.

Abstract: In an example, a processor comprises an ancillary print agent distribution module to determine instructions for a print control module. The print control module may be to control the distribution of print agent onto a first region of a layer of build material in an object fabrication chamber in an additive manufacturing process in which at least one object is generated by selective solidification of each of a plurality of layers of build material and the selective solidification of build material is determined by the distribution of at least one print agent. The instructions determined by the ancillary print agent distribution module may be to cause the print control module to control the distribution of print agent in a second region of a layer of build material in an object fabrication chamber as part of a process which is ancillary to object generation. The first and second regions may be spatially distinct.

Abstract: In an example an additive manufacturing system for generating a three-dimensional object by processing successive layers of build material comprises a controller to: receive data relating to a three-dimensional object to be generated; calculate, based at least in part on the data relating to the three-dimensional object, an estimated time to process each layer of build material; determine the longest time of said estimated times; and configure the additive manufacturing system to process each layer of build material in a time which is the same, within a predetermined tolerance, for all of the layers, and which is at least as long as the determined longest time.

Abstract: In an example, a data unit includes a mounting to removably mount the data unit on a receiving portion of an additive manufacturing build material container, a data source to provide data comprising a plurality of additive manufacturing parameters and a communications interface to communicate with a reader of an additive manufacturing build material processing apparatus. The communications interface is to transmit data from the data source to the additive manufacturing build material processing apparatus.

Abstract: Examples Include apparatuses and methods for generating three-dimensional objects. An example apparatus comprises an agent distributor and a wiping element disposed at a service location. The apparatus further comprises at least one airflow component disposed proximate the service location to generate airflow across the wiping element to reduce build material collection on the wiping element.

Abstract: An apparatus and method for generating a three-dimensional object. The apparatus includes a build material area, at least one agent distributor with a fluid reservoir to store fluid agent and at least one fluid ejection die to selectively eject fluid agent in the build material area. A cooling system to remove heat from the at least one fluid ejection die has a heat sink. The at least one fluid ejection die is in thermal contact with the heat sink via the fluid agent of the fluid reservoir.