A printer is described that comprises a print chamber and an electromagnet moveable within the print chamber. The electromagnet has an on state and an off state. The electromagnet is to collect magnetic powder within the print chamber when in the on state, and to deposit magnetic powder when in the off state.

An additive manufacturing apparatus is disclosed. The apparatus includes a build platform, a scanning unit and a preheating arrangement. Material is operatively deposited on the build platform to form a material bed, with a surface of the material bed defining a material area. The scanning unit is configured to consolidate deposited material in a scan area on the surface of the material bed, wherein the scan area forms part of and is substantially smaller than the material area. The preheating arrangement is configured to focus energy onto the surface of the material bed substantially in the scan area and not in the remainder of the material area. A method of preheating material in an additive manufacturing apparatus, a method of forming an object by additive manufacturing and a preheating arrangement for an additive manufacturing apparatus are also disclosed.

Apparatus (1) for additively manufacturing three-dimensional objects (2) by means of successive layerwise selective irradiation and consolidation of layers (3) of a build material (4) which can be consolidated by means of an energy source.

In one example, a system for loading build material into a portable build unit having a platform on which objects are printed and a build material supply container next to the platform. The system includes a build material dispenser, a conveyor to move the build unit and/or the dispenser, and a controller operatively connected to the dispenser and the conveyor. The controller is programmed to, with the build unit and the dispenser in a fill position, cause the dispenser to dispense build material into the supply container, cause the conveyor to move the build unit and/or the dispenser to and/or from the fill position, and, while the conveyor moves the build unit and/or the dispenser to and/or from the fill position, cause the dispenser to dispense build material on to the platform.

In one example, a system for loading build material into a portable build unit having a platform on which objects are printed and a build material supply container next to the platform. The system includes a build material dispenser, a conveyor to move the build unit and/or the dispenser, and a controller operatively connected to the dispenser and the conveyor. The controller is programmed to, with the build unit and the dispenser in a fill position, cause the dispenser to dispense build material into the supply container, cause the conveyor to move the build unit and/or the dispenser to and/or from the fill position, and, while the conveyor moves the build unit and/or the dispenser to and/or from the fill position, cause the dispenser to dispense build material on to the platform.

Examples of a system for additive manufacturing are described. The system comprises a powder reservoir for storing the metal powder operatively coupled to a working chamber that includes a powder feeder with a housing that defines an inner cavity with an inlet and a number of nozzles in communication with the inner cavity of the powder feeder defining an outlet of the feeder. The number of nozzles are positioned around a center axis of a generated energy beam. A powder feeder's driver is configured to drive flow of the powder through the nozzles directly into a beam path such that an exact amount of the powder is placed into the beam path to be melted or sintered onto a powder bed.

Examples of a system for additive manufacturing are described. The system comprises a powder reservoir for storing the metal powder operatively coupled to a working chamber that includes a powder feeder with a housing that defines an inner cavity with an inlet and a number of nozzles in communication with the inner cavity of the powder feeder defining an outlet of the feeder. The number of nozzles are positioned around a center axis of a generated energy beam. A powder feeder's driver is configured to drive flow of the powder through the nozzles directly into a beam path such that an exact amount of the powder is placed into the beam path to be melted or sintered onto a powder bed.

A three-dimensional printing system includes a build plate, a carriage, a housing assembly covering the carriage, and a printhead. The build plate includes a lateral print area having a length along an X-axis and a width along a Y-axis. The carriage has a major axis along the Y-axis that spans the width of the lateral print area. The printhead is mechanically, fluidically, and electrically coupled to the carriage. The printhead includes a printhead housing that cooperates with the housing assembly to separate a print zone containing the lateral print area from connected internal components of the printhead and the carriage. The carriage is configured to scan along the X-axis and the printhead is configured to scan along the Y-axis supported by the carriage to address the entire lateral print area.

A three-dimensional printing system includes a build plate, a carriage, a housing assembly covering the carriage, and a printhead. The build plate includes a lateral print area having a length along an X-axis and a width along a Y-axis. The carriage has a major axis along the Y-axis that spans the width of the lateral print area. The printhead is mechanically, fluidically, and electrically coupled to the carriage. The printhead includes a printhead housing that cooperates with the housing assembly to separate a print zone containing the lateral print area from connected internal components of the printhead and the carriage. The carriage is configured to scan along the X-axis and the printhead is configured to scan along the Y-axis supported by the carriage to address the entire lateral print area.

A build material dispensing device may include a material spreader to spread an amount of build material along a build platform, and at least one hopper for dispensing the build material. The at least one hopper dispenses a plurality of doses of the build material in front of the progression of the material spreader as the material spreader is moved over the build platform.