Figure 73 is a schematic diagram of a manufacturing process. The diagram shows a rectangular shaped tank split into three cube shaped compartments. One side of the tank is removed to reveal what is going on inside. All three compartments have a movable solid platform controlled by a piston below it. Above the platform the compartment is filled with powder and the surface level of the powder is the same in all three compartments. The inner separating walls between the compartments stop at the level of the powder surface. Outer compartments: The piston is labelled 'Powder feed piston' and the powder above the platform is labelled 'Powder feed supply'. An arrow indicates that the piston is pushing the platform up. Centre compartment: The compartment is labelled 'Build chamber' and the piston is labelled 'Build piston'. An object labelled 'Sintered part' is resting on the platform. An arrow indicates that the piston is allowing the platform to move down. A solid cylindrical object labelled 'Levelling roller' is situated on the surface of the powder and a direction arrow indicates that it rolls across the top of all three compartments. The roller picks up powder from the powder feed chambers and deposits it on the sintered part in the centre build chamber as it moves to and fro across the surface of the powder. Situated above the tank is a laser assembly identical to that in Figure 72 with a laser beam directed down on to the top surface of the sintered part.