Abstract: A system includes a build platform having a bottom surface and a top surface. A plurality of apertures receives the build material on the build platform. A vibration generator is coupled to the build platform to vibrate the build platform and move the build material on the build platform. An air handler applies airflow to the build platform in a first airflow mode and a second airflow mode. In the first airflow mode, the build material from the build platform is removed through the plurality of apertures.

Abstract: An example of an apparatus is provided. The apparatus includes a container to store a powder. The apparatus includes a flow generator to move a gas to the container. The flow generator is to move the gas at a first velocity and a second velocity, the first velocity to fluidize the powder in a fluidized state, and the second velocity to pass through stationary powder in a powder pack. The apparatus includes pressure sensors to measure pressures in the container. The apparatus includes a measurement engine in communication with the pressure sensors, wherein the measurement engine is to calculate a mass of the powder based on a fluidized pressure differential and based on a pack pressure differential.

Abstract: A system includes a build platform having a bottom surface and a top surface. A plurality of apertures receives the build material on the build platform. A vibration generator is coupled to the build platform to vibrate the build platform and move the build material on the build platform. An air handler applies airflow to the build platform in a first airflow mode and a second airflow mode. In the first airflow mode, the build material from the build platform is removed through the plurality of apertures.