Fig 4Hybrid stepper1.8° per full stepfull step · A+
full step 0 of 200shaft 0.0°rpm 0
S pole, grips the rotor's top teethN pole, grips the hidden lower teethEnergised coils and the shaft pointerA NEMA 17 with its rear end bell off. The rotor has 50 teeth and there are 8 stator poles, each a quarter tooth out of line with the next. Every full step moves the current to the next coil pair (A+, B+, A−, B−) and the nearest rotor teeth jump a quarter tooth to line up with it: 1.8°, 200 steps a turn. Half stepping puts both coils on between full steps, landing halfway at 0.9°. 1/16 microstepping drives the coils with a sine and a cosine, so the field turns in 16 small moves per step: watch the scope turn into smooth waves. Follow the white dot on one rotor tooth: four full steps carry it exactly one tooth along.