Judgment be much torque: torque is one of the main parameters of step motor. Large load, with big torque motor. Torque indicator, shape of large motor. Judge: high speed motor speed, motor is larger, less inductance should be the phase current, to increase the input power. And the power supply voltage is high in the selected drive. Select the installation specifications of the motor: such as 42, 57, 86, 110, is mainly related with the torque requirements.
To determine the precision positioning and vibration requirements: judging whether to subdivide, how much the subdivision. Based on the motor current, breakdown and voltage drive.