Apparatus for manufacturing a three-dimensional object from a powder, the apparatus comprising: a work surface; a build bed having a build area, the build area being comprised within the work surface, wherein successive layers of said three-dimensional object are formed in the build bed; a first powder supply module fixedly arranged on a first side of the work surface, outward from a first side of the build bed; a second powder supply module fixedly arranged on a second side of the work surface, outward from a second side of the build bed; a first powder distribution sled operable to distribute powder dosed to the work surface from the first powder supply module while moving in a first direction from the first side of the work surface towards the second side of the work surface, and from the second powder supply module while moving in a second direction from the second side of the work surface towards the first side of the work surface, so as to form a layer of powder within the build area, the first powder distribution sled being driveable along a first axis across the build area; and a print sled operable to deposit a pattern of fluid onto the layer of powder within the build area to define a cross section of said object in said layer, the print sled being driveable along a second axis across the build area; wherein the first axis is parallel to, or coaxial with, the second axis; wherein the first powder distribution sled comprises a first powder distribution device for distributing the powder; wherein the print sled comprises one or more droplet deposition heads for depositing the fluid, a first radiation source assembly (L2; L3) located on one side of the one or more droplet deposition heads, and a second radiation source assembly (L3; L2) located on the other side of the one or more droplet deposition heads; and wherein the first powder distribution sled further comprises a third radiation source assembly. a work surface; a build bed having a build area, the build area being comprised within the work surface, wherein successive layers of said three-dimensional object are formed in the build bed; a first powder supply module fixedly arranged on a first side of the work surface, outward from a first side of the build bed; a second powder supply module fixedly arranged on a second side of the work surface, outward from a second side of the build bed; a first powder distribution sled operable to distribute powder dosed to the work surface from the first powder supply module while moving in a first direction from the first side of the work surface towards the second side of the work surface, and from the second powder supply module while moving in a second direction from the second side of the work surface towards the first side of the work surface, so as to form a layer of powder within the build area, the first powder distribution sled being driveable along a first axis across the build area; and a print sled operable to deposit a pattern of fluid onto the layer of powder within the build area to define a cross section of said object in said layer, the print sled being driveable along a second axis across the build area; wherein the first axis is parallel to, or coaxial with, the second axis; wherein the first powder distribution sled comprises a first powder distribution device for distributing the powder; wherein the print sled comprises one or more droplet deposition heads for depositing the fluid, a first radiation source assembly (L2; L3) located on one side of the one or more droplet deposition heads, and a second radiation source assembly (L3; L2) located on the other side of the one or more droplet deposition heads; and wherein the first powder distribution sled further comprises a third radiation source assembly.