The NEMA 17 Stepper Motor is a bipolar (two-coil) hybrid stepper with a 42 x 42 mm faceplate, the standard motor in 3D printers and CNC machines. Its step angle is 1.8 degrees, so a full turn takes 200 steps, or 3200 steps with 1/16 microstepping on the driver. Depending on the model, the body is 34–48 mm long, phase current is 1.2–2 A and holding torque is about 0.3–0.5 Nm. Its 4 wires (A+, A-, B+, B-) belong to two coils; the pairs are found by measuring resistance with a multimeter. Since a microcontroller cannot supply this current, it is used with a driver such as the A4988, DRV8825 or TMC2208: the Arduino, ESP32 or Pico only sends pulses to the STEP and DIR pins, and the motor runs from a separate 12–24 V supply. The current is limited with the driver's Vref, a 100 µF capacitor goes across the supply, and the motor should never be unplugged while the driver is powered. It is used in 3D printers, CNC machines, camera sliders, automatic curtains, plotters and robot arms.