Abstract: A calibration system for automatically resetting the effective vertical Z coordinate corresponding to the tip of an extruder of a printing head with filler material filament for 3D printers provided with a printing plane movable along the vertical Z axis, wherein the printing head is installed on a carriage for moving the extruder on the horizontal plane XY, includes at least one touch probe unit associated with and operatively connected to the extruder, specifically arranged between the carriage and the extruder itself, including: at least one movable support, at least one touch probe, at least one extruder support, at least one coupling system, at least one carriage, at least one extruder. The movable support is substantially a mechanical spring-operated sliding system, configured to allow the extruder to travel the path needed to activate the touch probe during the touching operation and to return to the printing position.

Abstract: An automatic calibration system for calibrating the parallelism between a printing plane of a 3D printer and a virtual plane on which the extruder of the 3D printer moves, to align the printing plane with the virtual plane on which the extruder moves, includes: at least one extruder, or a printing head on which the extruder itself is mounted, movable on a horizontal plane; at least one device for measuring the distance of the printing plane associated with the extruder or with a printing head; a movable printing plane along the vertical axis Z, the plane being equipped with at least three non-aligned actuators, which are controllable and operable independently of each other; a central control unit (MCU or PLC) of the calibration system and of all the parts thereof.