Apparatus for manufacturing a three-dimensional object from a powder, the apparatus comprising: a build bed having a build area, wherein successive layers of said three-dimensional object are formed in the build bed; a powder distribution sled operable to distribute a layer of powder within the build area, the powder distribution sled being driveable in a first direction along a first axis, across the build area, and driveable in a second direction, opposite to the first direction, along the first axis; and a print sled operable to deposit a pattern of radiation absorbing fluid onto the layer of powder within the build area to define the cross section of said object in said layer, the print sled 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 powder distribution sled and the print sled are independently movable; wherein the print sled comprises one or more droplet deposition heads for depositing the radiation absorbing fluid, a first radiation source assembly, and a second radiation source assembly; wherein the first radiation source assembly is located on one side of the one or more droplet deposition heads, in the second direction relative to the one or more droplet deposition heads; wherein the second radiation source assembly is located on the other side of the one or more droplet deposition heads, in the first direction relative to the one or more droplet deposition heads, or wherein the second radiation source assembly is located on the same side with respect to the one side of the one or more droplet deposition heads, in the second direction relative to the one or more droplet deposition heads; wherein the powder distribution sled comprises a powder distribution device for distributing the powder, a third radiation source assembly and a fourth radiation source assembly; wherein the third radiation source assembly is located on one side of the powder distribution device, in the second direction relative to the powder distribution device; and wherein the fourth radiation source assembly is located on the other side of the powder distribution device, in the first direction relative to the powder distribution device, or wherein the fourth radiation source assembly is located on the same side with respect to the one side of the powder distribution device, in the second direction relative to the powder distribution device. a build bed having a build area, wherein successive layers of said three-dimensional object are formed in the build bed; a powder distribution sled operable to distribute a layer of powder within the build area, the powder distribution sled being driveable in a first direction along a first axis, across the build area, and driveable in a second direction, opposite to the first direction, along the first axis; and a print sled operable to deposit a pattern of radiation absorbing fluid onto the layer of powder within the build area to define the cross section of said object in said layer, the print sled 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 powder distribution sled and the print sled are independently movable; wherein the print sled comprises one or more droplet deposition heads for depositing the radiation absorbing fluid, a first radiation source assembly, and a second radiation source assembly; wherein the first radiation source assembly is located on one side of the one or more droplet deposition heads, in the second direction relative to the one or more droplet deposition heads; wherein the second radiation source assembly is located on the other side of the one or more droplet deposition heads, in the first direction relative to the one or more droplet deposition heads, or wherein the second radiation source assembly is located on the same side with respect to the one side of the one or more droplet deposition heads, in the second direction relative to the one or more droplet deposition heads; wherein the powder distribution sled comprises a powder distribution device for distributing the powder, a third radiation source assembly and a fourth radiation source assembly; wherein the third radiation source assembly is located on one side of the powder distribution device, in the second direction relative to the powder distribution device; and wherein the fourth radiation source assembly is located on the other side of the powder distribution device, in the first direction relative to the powder distribution device, or wherein the fourth radiation source assembly is located on the same side with respect to the one side of the powder distribution device, in the second direction relative to the powder distribution device.