Build Material Spreading Apparatuses for Additive Manufacturing

A build material spreading apparatus, including:

• a supply volume to contain build material,
• a spreader roller movable, and
• a controller to adjust the quantity of build material needed to form a layer to be spread, wherein the controller is to:
• pilot the supply volume to supply a predetermined quantity of build material;
• move the spreader roller to form a layer of build material;
• determine a quantity of build material in excess after formation of the layer of build material;
• adjust, based on the determined quantity of build material in excess, the predetermined quantity of build material to be subsequently supplied by the supply volume.

A build material spreading method, including:

• spreading a first layer of build material over a build area,
• determining an excess amount of build material dispensed to form the first layer,
• calculating an amount of build material needed to form a second layer as a function of the excess amount of build material dispensed to form the first layer,
• piloting a build material dispenser to provide a movable spreader with the determined amount of build material, and
• spreading a second layer of build material over the build area using the build material provided by the build material dispenser.