Stepper motors are used in a wide variety of applications, including robotics, automation, and CNC machines, where precise and repeatable motion control is critical. Stepper motors work by dividing a complete rotation into a series of discrete steps, each corresponding to a fixed angular displacement. The number of steps per revolution is determined by the design of the motor. In this paper, we will explore the concepts of full and half-steps in stepper motors.
Full stepping is the simplest and most common method of controlling stepper motors. A standard hybrid stepper motor has 200 rotor teeth, meaning that it takes 200 steps for the motor to rotate one revolution, and one step has a rotation angle of 1.8°. Typically, the full-stepping mode involves energizing one or more coils, through which the current will generate a magnetic field with which the rotor will align; by sequentially applying voltages to different phases, the rotor will rotate a specific angle and eventually reach the desired position.
Half-stepping is a more advanced technique that improves the resolution of stepper motors and reduces torque pulsation. In half-stepping, two coils are energized simultaneously, creating an intermediate magnetic field between the two coils. This intermediate field aligns the rotor between two stable positions at full stepping, effectively doubling the number of steps per revolution. Half-stepping results in smoother and more accurate motor motion because the intermediate position reduces step length and mitigates torque fluctuations.
In practice, the choice of full or half stepping depends on the requirements of your application, including the required resolution, torque and speed. Full-stepping is typically suitable for applications requiring moderate accuracy and torque, while half-stepping is more suitable for applications requiring higher accuracy and smoother motion.