Patent attributes
A dispensing system for an additive manufacturing includes a powder source that contains powder to form an object, and an array of nozzles positioned at a base of the powder source over a top surface of a platen where the object is to be formed. The powder flows from the powder source through the nozzles to the top surface. A respective powder wheel in each nozzle controls a flow rate of the powder. Each wheel has multiple troughs on surface of the wheel. When a motor rotates the wheel, the troughs transport the powder through the nozzle. The rotation speed of the wheel controls the flow rate. For solid parts of the object, the wheel rotates and allows the powder to be deposited on the top surface. For empty parts of the object, the wheel remains stationary to prevent the powder from flowing to the surface.