The PCR is the core machine of the system: it performs continuous compaction of the incoming powder layer, using two motorised belts with converging axes and a set of intermediate drive rollers. The belts are driven by electronic speed control and have adjustable compaction geometry. The compactor body is set up to facilitate the replacement of the upper belt, by opening one side of the machine and some pneumatic cylinders, which lift the belt and move it in the suitable position.