Powder spreading apparatus and system

Abstract

A powder spreading apparatus includes a hopper having a first end, a second end opposite from the first end, a front wall, a rear wall opposite from the front wall, and a floor. The front wall, the rear wall, the first end, the second end, and the floor define an interior. An impeller is disposed within the interior of the hopper. The impeller includes a plurality of circumferentially spaced flutes and is configured to rotate about an impeller axis that extends from the first end of the hopper to the second end of the hopper to deposit powder onto a print area. A spreader rod is coupled to the hopper and extends along a spreader rod axis parallel to the impeller axis. The spreader rod is configured to rotate about the spreader rod axis to smooth the powder as it is deposited onto the print area. A powder spreading method is disclosed that operates an impeller to start depositing powder from a hopper into a print area located within a build box as a gantry moves the hopper in a first direction across the print area; operating a spreader rod to smooth out the powder on the print area as the gantry moves the hopper and the spreader rod across the print area in the first direction; and upon the gantry reaching a predetermined position in the print area, stopping the impeller to stop depositing the powder while continuing to operate the spreader rod.