An additive manufacturing machine (910) includes a build platform (908) extending within a horizontal plane (H) and a gantry (930) positioned above the build platform (908) and defining a build area (932). A build unit (920) includes a powder dispenser (906) for discharging a layer of additive powder (902) and an energy source (922) for selectively directing energy toward the layer of additive powder (902) to fuse portions of the layer of additive powder (902). The gantry (930) movably supports the build unit (920) within the build area and a powder supply system (900) is positioned below the gantry (930) and extends between a powder supply source (940) and the powder dispenser (906).