Laser 3D printer

A laser 3D printer comprising a tubular compartment, which has a vertical longitudinal axis and is limited by a first side wall, which extends about the longitudinal axis itself;

• a lifting platform engaged in a sliding manner in the tubular compartment;
• a feeding unit for feeding a powdered material onto the lifting platform;
• a laser printing head for sintering the powdered material laid on the lifting platform;
• and a collection chamber, which extends about the first side wall of the tubular compartment, has an outlet for the powdered material, and is limited by a second side wall and a bottom wall configured so as to feed the powdered material towards the outlet itself;
• the tubular compartment having at least one opening made through the first side wall for connecting together the tubular compartment and the collection chamber;
• and being characterized in that the tubular compartment is inserted within the collection chamber so that the outlet is located beneath the tubular compartment, wherein an annular channel is defined between the first side wall and the second side wall and communicates with the tubular compartment via the at least one opening of the first side wall, the annular channel having a substantially U-shaped inlet section and is closed by a plane (P) on a fourth side thereof, wherein the bottom wall of the collection chamber is inclined inwardly and downwardly towards the outlet for centrally feeding the powered material to the outlet.