Apparatus, methods, and systems for calibrating 3D printers

An apparatus comprising:

• an extruder body;
• a heat block;
• a nozzle support structure that operatively attaches a nozzle to a 3D printer and comprises a strained region that experiences a surface strain of between approximately 1×10−7 and approximately 1×10−4 responsive to a contact between the nozzle and a print surface;
• and
• a semiconductor strain gauge that is attached to the strained region and operable to generate an analog signal and output a digital signal responsive to the surface strain, the semiconductor strain gauge comprising a gauge factor of between approximately 80 and approximately 200, the digital signal being detectable by the 3D printer, the nozzle support structure comprising:
• a nozzle block extending outwardly from the extruder body for attachment to the nozzle and the heat block;
• a hinge connector arm extending outwardly from the extruder body;
• and
• a flexure bearing hinge that extends between the nozzle block and the hinge connector arm and flexes when a tip of the nozzle contacts the print surface,
• wherein a flexure of the flexure bearing hinge causes the strained region to experience the surface strain.