A device for a printer for printing with cementitious material, comprising: a first tubular body having a first end adapted for coupling to a first end of an extrusion tubular member, the first tubular body comprising a rolling bearing ring; a printing head comprising: a second tubular body coupled to a second end of the first tubular body in fluid communication; a first member coupled to the second tubular body in fluid communication; and an extrusion nozzle for discharging the cementitious material, the extrusion nozzle being coupled to the second tubular body in fluid communication by interposition of the first member, which is coupled to the extrusion nozzle in fluid communication; and means for rotating the printing head, said means being coupled to the first tubular body so as to rotate the second tubular body around a cylindrical axis thereof, the means comprising a motor; characterized in that: the first member is C- or U- shaped; and the device further comprises means for stopping discharge of the cementitious material, said means comprising a second member adapted to fit within an open end of the first member so that it blocks an opening of the second tubular body for passage of the cementitious material from the second tubular body to the extrusion nozzle, and said means further comprising a mechanism for selectively moving the second member between at least two positions: a first position in which the second member is within the open end of the first member thereby blocking the passage of the cementitious material, and a second position in which the second member is not within the open end of the first member thereby not blocking the passage of the cementitious material. a first tubular body having a first end adapted for coupling to a first end of an extrusion tubular member, the first tubular body comprising a rolling bearing ring; a printing head comprising: a second tubular body coupled to a second end of the first tubular body in fluid communication; a first member coupled to the second tubular body in fluid communication; and an extrusion nozzle for discharging the cementitious material, the extrusion nozzle being coupled to the second tubular body in fluid communication by interposition of the first member, which is coupled to the extrusion nozzle in fluid communication; and means for rotating the printing head, said means being coupled to the first tubular body so as to rotate the second tubular body around a cylindrical axis thereof, the means comprising a motor; a second tubular body coupled to a second end of the first tubular body in fluid communication; a first member coupled to the second tubular body in fluid communication; and an extrusion nozzle for discharging the cementitious material, the extrusion nozzle being coupled to the second tubular body in fluid communication by interposition of the first member, which is coupled to the extrusion nozzle in fluid communication; and means for rotating the printing head, said means being coupled to the first tubular body so as to rotate the second tubular body around a cylindrical axis thereof, the means comprising a motor; characterized in that: the first member is C- or U- shaped; and the device further comprises means for stopping discharge of the cementitious material, said means comprising a second member adapted to fit within an open end of the first member so that it blocks an opening of the second tubular body for passage of the cementitious material from the second tubular body to the extrusion nozzle, and said means further comprising a mechanism for selectively moving the second member between at least two positions: a first position in which the second member is within the open end of the first member thereby blocking the passage of the cementitious material, and a second position in which the second member is not within the open end of the first member thereby not blocking the passage of the cementitious material. the first member is C- or U- shaped; and the device further comprises means for stopping discharge of the cementitious material, said means comprising a second member adapted to fit within an open end of the first member so that it blocks an opening of the second tubular body for passage of the cementitious material from the second tubular body to the extrusion nozzle, and said means further comprising a mechanism for selectively moving the second member between at least two positions: a first position in which the second member is within the open end of the first member thereby blocking the passage of the cementitious material, and a second position in which the second member is not within the open end of the first member thereby not blocking the passage of the cementitious material. a first position in which the second member is within the open end of the first member thereby blocking the passage of the cementitious material, and a second position in which the second member is not within the open end of the first member thereby not blocking the passage of the cementitious material.