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Pulse Filament Flow Sensor

3D Printing Electronics MatterHackers
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Sensor that allows 3D printers to detect filament jams and runouts. Allows for closed loop control of extrusion. Printer can take pause or take action if a problem is detected, and also automatically calibrate extrusion amount while printing. Uses a magnetic hall effect angle sensor to detect the rotation of a gear driven by the filament. Minimizes components by using a compliant mechanism to press and idler wheel against the filament, which in turn spins the sensor gear. Interfaces with the printer’s controller using I²C.


  • Mechanical design (CAD) in Onshape
  • Electrical PCB design in KiCad
  • Wrote driver for Smoothieware to interface with sensor via I²C