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: 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: 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: An example method to determine an excess of build material in 3D printing includes providing an amount of build material, spreading the amount of build material to form a layer of build material on a build platform and to leave any excess build material on an excess zone having visible marks thereon and analyzing the marks on the excess zone to determine an excess of build material at the excess zone.

Abstract: A method for reducing artefacts in printed objects comprises receiving print data to be printed by a printhead arrangement, the printhead arrangement being movable in a print direction and comprising a plurality of printhead dies, wherein printhead dies adjacent to each other comprise an overlap area when viewed in the print direction. The print data to be printed are modified near and/or at the overlap areas between printhead dies of the printhead arrangement to compensate for drop placement.

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: 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: Powder-fusing energy source control comprising the generating of printer control instructions to control a powder-fusing energy source based on a spectrophotometry measurement of build powder in a three-dimensional printing system.

Abstract: A three-dimensional printing system comprises a build unit, a three-dimensional printer and a controller. The build unit comprising a build chamber and a heater. The printer is configured to generate a build volume comprising a three-dimensional object within the build chamber and the heater is configured to heat the build chamber. The controller is configured to control the heater to heat the build chamber for a predetermined time period after the build volume is generated, to allow the object to crystallise.

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: An example of an additive manufacturing system is disclosed. The example disclosed herein comprises a controller. The controller is to generate a theoretical heatmap representing portions of a layer of build material heated during processing of a previously formed layer supplied to a build bed. The controller is also to calculate, based on the theoretical heatmap, an amount of build material needed in a next layer to be supplied to the build bed. The controller is further to instruct a supply module to supply the amount of build material to the build bed.

Abstract: An example method to determine an excess of build material in 3D printing includes providing an amount of build material, spreading the amount of build material to form a layer of build material on a build platform and to leave any excess build material on an excess zone having visible marks thereon and analyzing the marks on the excess zone to determine an excess of build material at the excess zone.

Abstract: According to one example, there is provided a method of preparing build material in a build material supply module. The method comprises moving a supply platform within a build material supply module in a predetermined manner to compact build material within the supply module.

Abstract: According to one example there is provided a build material supply system for a 3D printing system. The system comprises a feed tray for containing build material, a plate for removing build material from the feed tray and forming a pile of build material adjacent a spreader of the 3D printing system, and a sensor module to detect build material on the plate.

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: 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: 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.