Induction sensing method for locating center of metallic nozzle tip

A method of determining a location of a tip orifice in a metal nozzle for a print head of a 3D printer, the method comprising:

• providing the metal nozzle with tip orifice in a main body and a tip surface about the tips orifice;
• using an optical sensor to determine a location of a center of an inner diameter of the tip orifice on the tip surface of the metal nozzle;
• using an eddy current sensor to determine a location of a center of the tip surface of the metal nozzle, comprising the steps of
• moving the metal nozzle over the eddy current sensor in a predetermined motion path above the eddy current sensor held in a stationary position while the eddy current sensor samples the magnitude of inductance in a generated inductive field, thereby generating a curve representing the inductive field;
• and
• identifying a maximum amplitude of the curve to identify the center of the tip surface.