Abstract: A controller and method for layer-by-layer manufacturing of a three-dimensional object from a powder. The method includes, in a first direction across a build area: moving a droplet deposition unit and depositing a radiation absorber onto regions of a previously applied layer of powder; moving a first radiation source according to a first velocity profile whilst activating the first radiation source to fuse the regions of powder where the absorber has been deposited; moving a powder distributor according to a second velocity profile and distributing a fresh layer of powder; and moving a second radiation source whilst activating the second radiation source to preheat the fresh layer of powder. The method further includes adjusting the first and/or second velocity profiles to control a time interval between the passing of the first radiation source and the powder distributor.

Abstract: A method for recirculating powder in an apparatus for manufacturing a three-dimensional object from the powder. The powder recirculation method includes: providing powder in a powder repository, the powder being one of fresh powder, excess powder or a blend thereof; transferring the powder from the repository to a work surface; distributing the powder across a build surface and resulting in a portion of the powder defining excess powder; returning the excess powder back to the repository; monitoring the amount of powder in the repository relative to a predetermined amount of powder; and delivering fresh powder from a powder tank to the repository when the amount of powder in the repository is less than the predetermined amount and not delivering fresh powder when excess powder is being returned to repository and the amount of powder in the repository is greater than the predetermined amount of powder.

Abstract: A powder recirculation system for an apparatus for manufacturing a three-dimensional object (500) from powder is provided. The powder recirculation system comprises: a delivery path coupled to an outlet of a powder tank (410), the powder tank configured to store the powder; a powder repository (115) coupled to an outlet of the delivery path, the delivery path comprising a delivery mechanism for delivering the powder from the powder tank to the powder repository; a powder recirculation path coupled to an outlet (102) of the powder repository, wherein the powder recirculation path is configured to return first excess powder from the powder repository to the delivery path at a location (103, 104) upstream of the outlet of the powder tank.

Abstract: A method of manufacturing a three-dimensional object from a powder to form each layer of the object. The method includes the steps of driving a powder distribution sled in a first direction to distribute a layer of powder; driving a print sled in the first direction; driving the print sled and the powder distribution sled in a second direction; preheating the layer of powder by activating multiple radiation sources during various ones of the driving steps; during some of the driving steps, depositing a pattern of fluid onto the layer of powder; and sintering the powder on which fluid was deposited only in the second direction, by activating the at least one radiation source assembly during various ones of the driving steps in that direction. Repeating the above steps to distribute the next layer of powder.

Abstract: Apparatus (1) for manufacturing a three-dimensional object from a powder, the apparatus (1) comprising: a build bed (201) having a build area (190), wherein successive layers of said three-dimensional object are formed in the build bed (201); a powder distribution sled (300) operable to distribute a layer of powder within the build area (190), the powder distribution sled (300) being driveable in a first direction along a first axis, across the build area (190), and driveable in a second direction, opposite to the first direction, along the first axis; and a print sled (350) operable to deposit a pattern of fluid onto the layer of powder within the build area (190) to define the cross section of said object in said layer, the print sled (350) being driveable in the first direction along a second axis across the build area, and driveable in the second direction along the second axis; wherein the first axis is parallel to, or coaxial with, the second axis; wherein the print sled (350) comprises one or more drop

Abstract: Apparatus (1) for manufacturing a three-dimensional object from a powder, the apparatus (1) comprising: a build bed (201) having a build area (190), wherein successive layers of said three-dimensional object are formed in the build bed (201); a powder distribution sled (300) operable to distribute a layer of powder within the build area (190), the powder distribution sled (300) being driveable in a first direction along a first axis, across the build area (190), and driveable in a second direction, opposite to the first direction, along the first axis; and a print sled (350) operable to deposit a pattern of fluid onto the layer of powder within the build area (190) to define the cross section of said object in said layer, the print sled (350) being driveable in the first direction along a second axis across the build area, and driveable in the second direction along the second axis; wherein the first axis is parallel to, or coaxial with, the second axis; wherein the print sled (350) comprises one or more drop

Abstract: A stirring device for a powder tank of an apparatus for manufacturing a three-dimensional object. The stirring device is configured to rotate within the powder tank about an axis of rotation, and comprises a base plate and a strut.

Abstract: Apparatus (1) for manufacturing a three-dimensional object from a powder, the apparatus (1) comprising: a build bed (201) having a build area (190), wherein successive layers of said three-dimensional object are formed in the build bed (201); a powder distribution sled (300) operable to distribute a layer of powder within the build area (190), the powder distribution sled (300) being driveable in a first direction along a first axis, across the build area (190), and driveable in a second direction, opposite to the first direction, along the first axis; and a print sled (350) operable to deposit a pattern of fluid onto the layer of powder within the build area (190) to define the cross section of said object in said layer, the print sled (350) being driveable in the first direction along a second axis across the build area, and driveable in the second direction along the second axis; wherein the first axis is parallel to, or coaxial with, the second axis; wherein the print sled (350) comprises one or more drop

Abstract: Apparatus (1) for manufacturing a three-dimensional object from a powder, the apparatus comprising: a work surface (170); a build bed (201) having a build area (190), the build area (190) being comprised within the work surface (170), wherein successive layers of said three-dimensional object are formed in the build bed (201); a first powder supply module (2) fixedly arranged on a first side of the work surface (170), outward from a first side of the build bed (201); a second powder supply module (3) fixedly arranged on a second side of the work surface (170), outward from a second side of the build bed (201); a first powder distribution sled (300) operable to distribute powder dosed to the work surface (170) from the first powder supply module (2) while moving in a first direction from the first side of the work surface (170) towards the second side of the work surface (170), and from the second powder supply module (3) while moving in a second direction from the second side of the work surface (170) towards

Abstract: A powder dosing system for an apparatus for manufacturing a three-dimensional object from powder, the powder dosing system comprising: a rotating agitator arranged to agitate a supply of delivered powder by rotating through an agitation volume; a recirculation edge adjacent the agitation volume, arranged to allow excess agitated powder to freely flow over the recirculation edge and out of the dosing system; and a dosing blade arranged to dose a dosed volume of powder to a work surface comprising a build bed surface; wherein the dosing blade is arranged to sweep through a swept volume, which is located, in a vertical sense, above the agitation volume and overlaps, in a vertical sense, the agitation volume, such that the dosing blade doses agitated powder to the work surface.

Abstract: A method for the manufacture of three-dimensional objects is disclosed, utilising an independently operable printing sled (350) for sintering fusible powder and an independently operable powder distribution sled (300) for depositing a layer of fusible powder on the sintered layer. Since the printing sled and the powder distribution sled are independently operable, the time between sintering and deposition can be altered, dependent on the printing conditions and materials, resulting in an enhanced bond between the layers of the three-dimensional object.

Abstract: A powder recirculation system for an apparatus for manufacturing a three-dimensional object (500) from powder is provided. The powder recirculation system comprises: a delivery path coupled to an outlet of a powder tank (410), the powder tank configured to store the powder; a powder repository (115) coupled to an outlet of the delivery path, the delivery path comprising a delivery mechanism for delivering the powder from the powder tank to the powder repository; a powder recirculation path coupled to an outlet (102) of the powder repository, wherein the powder recirculation path is configured to return first excess powder from the powder repository to the delivery path at a location (103, 104) upstream of the outlet of the powder tank.

Abstract: An agitator for an apparatus for the manufacture of three-dimensional objects. The agitator comprises at least one blade coupled to a shaft, and extending outwardly from the shaft. Cavities are defined between the at least one blade and the shaft, such that movement of the agitator within a powder repository keeps the powder in a fluidised state and prevents the powder from agglomerating.

Abstract: A printer head for a thermal printer for building a three-dimensional model by sequential deposition of a plurality of cross-sectional layers, the thermal print head being movable relative to a material bed over a deposited layer. A protective sheet might be disposed between the thermal print head and deposited layer in a thermal printer according to the invention. Temperature control of the material bed to prevent warping of the model is provided by an independently heatable cover in contact with the surface of the material bed. The thermal print head further comprises a cooling element.