Abstract: Provided are a system, method and computer program product for generating three dimensional models for use by an additive manufacturing or 3D printing system, in which object model data defining one or more objects to be built by a three-dimensional printing apparatus is input and used to generate a three dimensional model for a protective structure to surround the one or more objects. A user is provided with selectable configuration options for the protective structure. The method includes presenting, via a user interface, selectable configuration options for a protective structure to be built around the one or more objects by the three-dimensional printing apparatus. In response to user selection of one or more configuration options via the user interface, a three dimensional model for the protective structure is automatically generated.

Abstract: In an example, a method comprises dispensing a first print agent onto a layer of build material in an additive manufacturing apparatus. The additive manufacturing apparatus may have a first print bar and a second print bar. The method may comprise determining a pattern of a first print agent to be applied to a layer of build material, dispensing a first portion of the determined pattern of the first print agent onto the layer of build material from the first print bar and dispensing a second portion of the determined pattern onto the layer of build material from the second print bar.

Abstract: A method is described in which model data describing a three-dimensional object is received. A first offset is applied to a surface of the object, the first offset being applied to the model data. The model data is converted to voxel data, and a second offset is applied to the surface of the object, the second offset being applied to the voxel data.

Abstract: An apparatus has a processor and a machine-readable storage medium storing machine-readable instructions executable by the processor. The processor is to create a 3D print job defining a spatial arrangement of objects to be printed such that each object or each object portion is arranged in a region or regions having a build material layer thickness corresponding to a user-specified build material layer thickness and such that objects or object portions having different build material layer thicknesses are arranged in different regions. Different build material layer thicknesses may be user-specified for different objects or different object portions.

Abstract: A method is disclosed in which print instructions for a 3D print job are received which including a plurality of layers to be printed on a layer-by-layer basis to form a 3D object. The print instructions are executed using at least one nozzle whilst performing a nozzle test in a plurality of layers of the 3D print job. The nozzle test results for each layer of the plurality of layers is compared to stored nozzle data. A current nozzle health status is determined based upon the comparison. A corrective action is triggered if the health status is non-compliant with a pre-determined threshold. An apparatus and a machine-readable storage medium comprising instructions executable by a processor are also disclosed.

Abstract: A method of printing an envelope for encapsulating at least one 3D printed object, the envelope allowing for removal of the at least one 3D printed object from an additive manufacturing system, the method comprising: monitoring a printing queue for one or more print jobs; determining a size of at least one dimension of the envelope based on the size of the one or more queued print jobs; commencing printing of the one or more queued print jobs and the envelope; and varying the size of the at least one dimension in response to changes in one or more print jobs in the printing queue.

Abstract: In an example, a method includes receiving, at least one processor, voxelised object model data describing at least part of an intended fabrication chamber content to be generated using additive manufacturing. The voxelised object model data may be derived from a first data set modelling a first object as 2D slices and a second data set modelling a second object as a 3D mesh. Data within the voxelised object model data which is derived from the first data set may be identified, and a geometrical transformation may be applied thereto.

Abstract: In an example, a method includes receiving, by at least one processor, object model data describing a first object to be generated in additive manufacturing and an intended object generation location of the first object, wherein the intended object generation location is a relative location within a generic fabrication chamber. The method may further comprise determining, by at least one processor, a location for generation of the first object in a first fabrication chamber, wherein the first fabrication chamber is an intended fabrication chamber of object generation. The location may be an absolute location in the first fabrication chamber which corresponds to the relative location within the generic fabrication chamber.

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: 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: An apparatus has a processor and a machine-readable storage medium storing machine-readable instructions executable by the processor. The processor is to create a 3D print job defining a spatial arrangement of objects to be printed such that each object or each object portion is arranged in a region or regions having a build material layer thickness corresponding to a user-specified build material layer thickness and such that objects or object portions having different build material layer thicknesses are arranged in different regions. Different build material layer thicknesses may be user-specified for different objects or different object portions.

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: A method of printing on a printable medium is disclosed. The method of printing may use a print head having a plurality of nozzles. The printable medium may have a leading edge and a defined zone adjacent to the leading edge. The print head may deposit print agent onto the printable medium via the plurality of nozzles during successive printing passes. The method may comprise printing outside, and not within, the defined zone on the printable medium using a first subset of nozzles of the plurality of nozzles. The method may further comprise printing within, and not outside, the defined zone on the printable medium using a second subset of nozzles of the plurality of nozzles.

Abstract: A circuit 108 for controlling a plurality of fluid dispense nozzles 202(N), the circuit 108 to change an order in which the fluid dispense nozzles 202(N) are actuated.

Abstract: A printing apparatus comprises a printhead and a controller. The printhead includes dies, each die comprising rows of nozzles, wherein, in an overlapping region, the rows of nozzles of two dies overlap in a first direction, in which a relative movement between the printhead and a print medium takes place during operation of the printing apparatus. The controller is to apply a first weaving mask to a first row of nozzles of a first die and a second weaving mask to a second row of nozzles of the first die, the second weaving mask being different from the first weaving mask, the weaving masks defining, independent of print data, which of the nozzles of the corresponding row are to be used for printing in the overlapping region.

Abstract: A method of printing is disclosed. The printing may involve printing on a printable medium using a print head having a plurality of nozzles, the printable medium having a leading edge and a defined zone adjacent to the leading edge. The print head may be to deposit print agent onto the printable medium via the plurality of nozzles during successive printing passes. The method may comprise: during a first printing pass, depositing print agent from a subset of the plurality of nozzles onto the printable medium outside the defined zone. The method may further comprise: advancing the printable medium by a defined distance. The method may further comprise: during a second printing pass, depositing print agent from a subset of the plurality of nozzles onto the printable medium within the defined zone.

Abstract: Print apparatus is controlled to execute a print operation comprising a plurality of print sweeps onto a print zone of a print substrate and a corresponding plurality of print advances of the print substrate between successive print sweeps. Print apparatus is controlled to execute an intermediate cutting operation between a pre-cut print sweep and a successive post-cut print sweep of the plurality of print sweeps.

Abstract: Print apparatus is controlled to execute a print operation comprising a plurality of print sweeps onto a print zone of a print substrate and a corresponding plurality of print advances of the print substrate between successive print sweeps. Print apparatus is controlled to execute an intermediate cutting operation between a pre-cut print sweep and a successive post-cut print sweep of the plurality of print sweeps.

Abstract: A method of printing on a printable medium is disclosed. The method of printing may use a print head having a plurality of nozzles. The printable medium may have a leading edge and a defined zone adjacent to the leading edge. The print head may deposit print agent onto the printable medium via the plurality of nozzles during successive printing passes. The method may comprise printing outside, and not within, the defined zone on the printable medium using a first subset of nozzles of the plurality of nozzles. The method may further comprise printing within, and not outside, the defined zone on the printable medium using a second subset of nozzles of the plurality of nozzles.

Abstract: A circuit 108 for controlling a plurality of fluid dispense nozzles 202(N), the circuit 108 to change an order in which the fluid dispense nozzles 202(N) are actuated.