Abstract: Some examples include a fusing system for an additive manufacturing machine including a carriage movable across a build zone along the x-axis, a thermic source mounted to the carriage, and a roller mounted to the carriage adjacent to the thermic source. A longitudinal section of an exterior surface of the roller is exposed to indirect heat from the thermic source. The roller is controlled to rotate during and outside of a spreading operation of the build material. The carriage is to maintain the roller within a radiative heat transfer area of the thermic source.

Abstract: Example systems relate to recoater movement. A non-transitory machine readable medium may contain instructions executable by a processor. The instructions may include instructions to change an action of a recoater in response to a determination that the recoater has reached a first location of a build area comprising build material. Instructions may further include instructions to lift the recoater in response to a determination that the recoater has reached a second location of the build area. Instructions may additionally include instructions to move the recoater over the second location at the lifted position, wherein the second location includes a build-up of the build material.

Abstract: In some examples, preheat three-dimensional (3D) printer build material can include a heating plate of a 3D printer to preheat build material from below the build material, where the heating plate is located adjacent to a build platform of the 3D printer, and a heater-spreader carriage of the 3D printer to preheat the build material from above the build material and spread the preheated build material from the heating plate to the build platform.

Abstract: Printers and associated printer maintenance methods and apparatus are disclosed. A printer including a work area; a temperature sensor to measure a first temperature value at a first region of the work area and a second temperature value at a second region of the work area; and a recoater to distribute a first amount of build material onto the first region and a second amount of the build material onto the second region in response to the first temperature value being a threshold different than the second temperature value.

Abstract: A three-dimensional (3D) printer and method for feeding powder to a build platform of the 3D printer, Incidental powder lost from the build platform is collected and fed to the build platform.

Abstract: In order to have ensure a proper dosing of a 3D printing system, it is disclosed a feeding mechanism for feeding build material to a surface that comprises: a receptacle to receive build material; and an outlet of the build material having a substantially quadrilateral opening with a first dimension and a second dimension orthogonal to one another; the outlet further comprising a third dimension orthogonal to the first dimension and the second dimension defining the height of the outlet, and the feeding mechanism being to selectively feed build material from the receptacle through the outlet onto a surface as the feeding mechanism moves along a travel direction over the surface, being such travel direction parallel to the first dimension of the outlet, the feeding mechanism further comprising an actuator to modify the magnitude of at least one of the second dimension or the third dimension outlet.

Abstract: In an example, a method includes acquiring, at a processor, object model data for an object to be generated in additive manufacturing, the object model data representing the object as a plurality of polygons. A virtual object space enclosing the object may be inspected from a plurality of discrete source points in a plane. For each of a plurality of distances from each source point, it may be determined if a polygon face is encountered, and if so, a counter may be set based on whether the polygon face is oriented towards the source point or away from the source point. Based on a content of the counter, it may be determined if a volume enclosed between two distances from a source point is a volume of the object.

Abstract: According to one example, there is provided a method of distributing build material in a 3D printing system. The method comprises moving a build material support positioned below a hopper, the movement to cause build material stored in the hopper to be deposited on the build material support, and moving a recoater to spread build material from the build material support over a build platform to form a layer of build material thereon, and to return any excess build material back to the build material support.

Abstract: In one example, a device to dispense a powder includes a hopper, an outlet from the hopper, a dispenser to dispense powdered build powder from the hopper through the outlet, and an agitator movable at the outlet intermittently at the urging of the dispenser.

Abstract: An apparatus may, in an example, include a build platform to receive a dose of build material and a build material spreader to spread the dose of build material over a length of the build platform wherein lateral portions of the build material spreader have a diameter smaller than a medial portion of the build material spreader.

Abstract: In one example, a powder holding system includes a receptacle having an interior to contain a column of powder and a meter to measure a shear force exerted on the interior of the receptacle by the column of powder.

Abstract: In some examples, with respect to feature protection for three-dimensional printing, a three-dimensional model of a three-dimensional object to be printed may be ascertained. A determination may be made as to whether a configuration of a three-dimensional model feature of the three-dimensional model matches a removable feature configuration from a set of removable feature configurations. Based on a determination that the configuration of the three-dimensional model feature of the three-dimensional model matches the removable feature configuration from the set of removable feature configurations, the three-dimensional model feature may be removed from the three-dimensional model to generate a modified three-dimensional model.

Abstract: According to an example, a recoater for a three-dimensional (3D) printer may include a cylindrical element having a surface to spread build material particles. The build material particles may have a specified average dimension and the surface may include a plurality of depressions that have dimensions that are smaller than the specified average dimension of the build material particles.

Abstract: In one example, a powdered build material supply system for additive manufacturing includes a supply deck, a dispenser to dispense a ribbon of powdered build material on to the supply deck, and a spreader to spread powdered build material from the ribbon over a work area adjacent to the supply deck.

Abstract: A system for forming an object, the system including: a carriage, wherein the carriage moves above an area for forming the object and laterally with respect to the area, the carriage comprising an electromagnetic radiation source to induce heating of material in the area; a thermal imaging device to image the area, wherein the thermal imaging device captures a plurality of sequential images; and a processor, wherein the processor uses the plurality of sequential images to create a temperature map of the area which includes compensation for the cooling which occurs during the movement of the carriage lateral to the area.

Abstract: A technology is described herein that includes a printer or a device with a fix or removable build unit. The printer has a spreader to spread a build material on the build unit and particularly, on a build platform of the build unit. The build unit further includes: a build material-retaining wall that blocks excess build materials overshooting an edge of the build platform as the spreader spreads the build material; and a frame that is disposed between the build platform and the build material-retaining wall in order to provide a stopping area for the blocked excess material. The build unit also have a trigger mechanism to detect a triggering condition and a wall-retraction mechanism coupled to the build material-retaining wall. The wall-retraction mechanism retracts the build material-retaining wall in response to the detected triggering condition.

Abstract: In an example implementation, a method of providing build powder for additive manufacturing of a three-dimensional (3D) object includes blending input powders into a blended powder for producing a 3D object. During the blending, a material strength value of each input powder can be determined. Based on the material strength value of each input powder, a ratio of the input powders can be calculated to achieve a specified material strength in the blended powder. The feed rate of the input powders can then be adjusted according to the ratio.

Abstract: According to an example, a recoater for a three-dimensional (3D) printer may include a cylindrical element having a surface to spread build material particles. The build material particles may have a specified average dimension and the surface may include a plurality of depressions that have dimensions that are smaller than the specified average dimension of the build material particles.

Abstract: The direction and distance for traversal by a media loaded into the printer is determined. A skew to be induced in a position of the media relative to a media feed direction axis is also determined. A scheme of motion for the rollers is selected and respective speeds for the first roller and the second roller are calculated. The first roller and the second roller are caused to be rotated at the respective speeds such that the skew is induced in the position of the media relative to the media feed direction.