Multiple sequential linear powder dispensers for additive manufacturing

An additive manufacturing system, comprising:

• a platen to support an object to be fabricated;
• a dispenser assembly positioned above the platen, the dispenser assembly including
• a support,
• a first dispenser supported by the support, the first dispenser configured to deliver a first dry powder in a first linear region that extends along a first axis, the first dispenser including
• a first common reservoir to hold the first dry powder,
• a plurality of first openings configured to deliver the first dry powder from the first common reservoir onto the platen, the plurality of first openings coupled to and extending from the first common reservoir and extending along the first axis, and
• a plurality of independently controllable first valves, each valve comprising a movable solid body configured to mechanically gate and independently control flow of the first dry powder through the plurality of first openings,
• a second dispenser supported by the support, the second dispenser configured to deliver a second dry powder in a second linear region that extends parallel to the first linear region and is offset from the first linear region along a second axis perpendicular to the first axis, the second dispenser including
• a second common reservoir to hold the second dry powder,
• a plurality of second openings configured to deliver the second dry powder from the second common reservoir onto the platen, the plurality of second openings coupled to and extending from the second common reservoir and extending along the first axis, and
• a plurality of independently controllable second valves, each valve comprising a movable solid body configured to mechanically gate and independently control flow of the second dry powder through the plurality of second openings;
• a drive system to move the support with the first dispenser and second dispenser moving together along the second axis such that the first linear region and second linear region sweep along the second axis to deposit the first dry powder and second dry powder consecutively along a swath over the platen to form a layer of powder;
• and
• an energy source configured to selectively fuse one or more voxels of the layer of powder.