Stepper motor: Torque-speed curve
For the user, the torque-speed curve is a decisive criterion for selecting a stepper. Let´s have a closer look!
Fig.: Stepper motor - Torque-speed curve
Holding Torque is called the torque which the motor produces when it has rated current flowing and is at standstill.
The Pull-in Torque shows the maximum value of torque at given speeds that the motor can start, stop or reverse without losing steps.
Without load the stepper can be started with maximum start frequency and then accelerated to the maximum possible operating frequency. With load, the maximum possible starting frequency, which is indicated by the pull-in curve, is reduced. If the motor is run outside of the pull-out torque curve, it will stall.