Achieving peak torque: Steppers vs. BLDC motors Motors with controllers/drives Basics In many motion control applications, achieving sufficient boost torque is a key requirement. While BLDC motors are often the default choice, small stepper motors can be a viable – and sometimes more efficient – alternative under peak torque conditions. Torque behavior in stepper motorsStepper motors are well-suited for dynamic applications that demand peak torque. Their performance depends largely on the specific application requirements and the size of the motor. As motor current increases, torque rises proportionally, up to the point where magnetic saturation sets the limit. Magnetic saturation and torque limits Magnetic saturation is influenced by the size of the stepper motor. In motors NEMA 14 and larger, it typically occurs at about 15–25% above the rated current. Beyond this point, supplying additional current no longer increases torque; instead, it only produces excess heat, causing the motor to warm up. With smaller steppers, torque can be doubled without reaching magnetic saturation. Integrated peak performance Nanotec’s PD1 series combines a NEMA 11 stepper motor with an integrated controller, supporting peak currents up to 3 A for maximum torque output.Thanks to field-oriented control, the motor stays significantly cooler, allowing safe operation with overcurrent and increased torque. At the same time, it prevents current increases once magnetic saturation is reached. Temperature monitoring further protects the motor by maintaining safe operating limits, even at peak torque.
