Stepper motors are useful for precision motion control, but their holding torque is usually limited. In many applications, higher holding torques are required to keep the motor shaft locked in place under external loads or vibration.
Methods to increase the holding torque of stepper motors
- Stepper motors come in a range of standard sizes, and larger sizes naturally have higher torque due to the increased coil size and magnet strength. If a standard-size stepper motor does not have enough holding torque for your application, increasing the size by one or two may make a big difference.
- Another simple solution is to increase the supply voltage to the motor. Stepper motors torque is proportional to the square of the applied voltage, so increasing the voltage can significantly increase the holding torque. However, higher voltages can also raise the temperature of the motor above its rating if it is run for long periods of time or at high speeds.
- Another approach is to use micro-stepping drives to provide higher-resolution control. Micro-stepping allows for finer position control and higher holding torque. Micro-stepping drives can increase holding torque by a factor of 5 or more compared to normal full-step operation.
There are several ways to increase the holding torque of a stepper motor. When increasing the holding torque, you also need to consider cost, size, heat, noise, and motor life to select a high-torque motor that fits your needs.