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: 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: 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: According to one example, there is provided a method of additive manufacturing that comprises obtaining data relating to a 3D object to be manufactured, forming a layer of build material on a build platform, applying a cooling agent in a pattern surrounding a portion of build material to be solidified, and applying energy only to the build material on which cooling agent is applied and to the surrounded portion of build material such that the surrounded portion of build material heats up sufficiently to coalesces, and such that build material on which cooling agent is applied is cooled by the cooling agent and is prevented from heating up sufficiently to coalesce.

Abstract: A reflector assembly for an additive manufacturing apparatus comprises a first reflector comprising a first reflector section having a first reflecting surface and a second reflector comprising a second reflector section having a second reflecting surface. The first reflector section is for reflecting radiation from a first radiating element located, in use, proximate to the first reflecting surface, and the second reflector section is for reflecting radiation from a second radiating element located, in use, proximate to the second reflecting surface. The first reflector section and the second reflector section are each formed of a ceramic material.

Abstract: An example of an additive manufacturing system is disclosed. The example disclosed herein comprises a build material distributor, a preheating source, and a controller. The build material distributor is to form build material layers from an intended build material having a color. The preheating source is to emit energy at a wavelength related to the intended build material color so that at least a 40% of the energy is absorbed by the build material. The controller is to receive printing instructions to print a 3D object, wherein the printing instructions define an area to be fused in a build material layer. The controller is also to instruct the build material distributor to form the build material layer. The controller is further to control the preheating source to emit energy to preheat a zone comprising the area to be fused.

Abstract: An example of an additive manufacturing system is disclosed. The example disclosed herein comprises a build material distributor, a color module, a preheating source, and a controller. The build material distributor is to form build material layers. The color module is to eject a composition that dyes a build material layer with a color. The preheating source is to emit energy at a wavelength related to the dyed build material color so that at least a 40% of the energy is absorbed by the dyed build material. The controller is to receive printing instructions to print a 3D object, wherein the printing instructions define an area to be fused in a build material layer. The controller is also to instruct the build material distributor to form the build material layer. The controller is to instruct the color module to eject the composition to color the build material from the build material layer in a zone comprising the area to be fused.

Abstract: A method and apparatus is described in which a signal indicative of an operation of a energy source of a 3D printer during a second predetermined time period commencing with the end of a first predetermined time period is obtained, the first predetermined time period commencing with an activation of the energy source, wherein the energy source is active throughout the first and second time periods; the obtained signal is compared with a reference signal; and it is determined, based on the comparison, whether the energy source is operating according to predetermined characteristics.

Abstract: An example apparatus to produce a three-dimensional object comprises a controller, a build area configured to receive a layer of particulate material, a printhead, and an ultraviolet light emitting diode energy source. The controller is to cause the printhead to deposit a liquid which absorbs ultraviolet radiation onto the layer of particulate material. The controller is further to cause the ultraviolet light emitting diode energy source to irradiate the liquid, after the liquid has been deposited onto the layer of particulate material, thereby to heat the liquid and cause a portion of the particulate material to solidify.

Abstract: Certain examples described herein relate to manufacturing a three-dimensional object. In some cases, a layer of build material is formed. An array of heat sources is controlled to selectively heat a sub-region of the layer of build material. Each heat source is individually addressable in the array to emit radiation independently of any other heat source in the array. Each heat source comprises a light-emitting diode, LED. In some cases, a fusing agent is deposited onto at least a part of the heated sub-region. Energy is applied at least to the deposited fusing agent to enable fusing of build material to fabricate a layer of the three dimensional object.

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: 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: 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: According to one aspect there is provided apparatus for generating a three-dimensional object. The apparatus comprises a first agent distributor to selectively deliver a coalescing agent onto portions of a layer of build material, a second agent distributor to selectively deliver a coalescence modifier agent onto portions of a layer of build material, and a controller to control the agent distributors to selectively deliver each of the agents onto a layer of build material in respective patterns derived from data representing a slice of a three-dimensional object to be generated, so that when energy is applied to the layer the build material coalesces and solidifies to form a slice of the three-dimensional object in accordance the patterns.

Abstract: According to one aspect there is provided apparatus for generating a three-dimensional object. The apparatus comprises a first agent distributor to selectively deliver a coalescing agent onto portions of a layer of build material, a second agent distributor to selectively deliver a coalescence modifier agent onto portions of a layer of build material, and a controller to control the agent distributors to selectively deliver each of the agents onto a layer of build material in respective patterns derived from data representing a slice of a three-dimensional object to be generated, so that when energy is applied to the layer the build material coalesces and solidifies to form a slice of the three-dimensional object in accordance the patterns.

Abstract: According to one aspect there is provided an apparatus for generating a three-dimensional object. The apparatus may include a first agent distributor to selectively deliver a coalescing agent onto portions of a layer of build material, a second agent distributor to selectively deliver a coalescence modifier agent onto portions of the layer of build material, and a controller to control the first and second distributors to selectively deliver each of the agent and the coalescence modifier onto the layer of build material in respective patterns derived from data representing a slice of a three-dimensional object to be generated, in which when energy is applied to the layer of build material, the build material coalesces and solidifies to form a slice of the three-dimensional object in accordance the patterns and the three-dimensional object has mechanical object properties that are related to the patterns.

Abstract: According to one aspect there is provided apparatus for generating a three-dimensional object. The apparatus comprises a first agent distributor to selectively deliver a coalescing agent onto portions of a layer of build material, a second agent distributor to selectively deliver a coalescence modifier agent onto portions of a layer of build material, and a controller to control the agent distributors to selectively deliver each of the agents onto a layer of build material in respective patterns derived from data representing a slice of a three-dimensional object to be generated, so that when energy is applied to the layer the build material coalesces and solidifies to form a slice of the three-dimensional object in accordance the patterns.

Abstract: According to one aspect there is provided apparatus for generating a three-dimensional object. The apparatus comprises a first agent distributor to selectively deliver a coalescing agent onto portions of a layer of build material, a second agent distributor to selectively deliver a coalescence modifier agent onto portions of a layer of build material, and a controller to control the agent distributors to selectively deliver each of the agents onto a layer of build material in respective patterns derived from data representing a slice of a three-dimensional object to be generated, so that when energy is applied to the layer the build material coalesces and solidifies to form a slice of the three-dimensional object in accordance the patterns.

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.