There are a huge number of advantages of using stepper motors over other types of motors in which stepper motors comprehensively outperform other types of motor. Conversely there are also performance areas that stepper motors are particularly poor at. However, for the purposes of this discussion we will explore some of the key advantages..
As will see in more detail below, the primary advantage of a stepper motor is that it enables exceptionally speed and positional control of motors. This is highly useful in applications such as robotics, dosing, industrial and production equipment.
In general the main use of a stepper motor is in motor control applications where positional accuracy is hugely important. Whereas a ‘traditional’ brushed DC motor turns constantly as soon as enough power is applied, a stepper motor can be turned an exact number of steps (up to 25600 steps in one complete revolution with a stepper motor drivers such as the ZD2). Depending on the number of degrees per step in the motor (this varies from motor to motor but in a standard 200 step motor this equates to 1.8 degrees per step) this can then enable the motor to move from one fixed position to another fixed position at any point of the circle. By using intelligent controllers such as the ZD series drivers, this movement can then be controlled very accurately with programmable acceleration and deceleration curves being applied. This is especially useful in dosing or process control applications where exceptional accuracy is crucial
The way in which a stepper motor performs and is able to operate is clearly heavily influenced by the build quality of that particularly motor. Conventional factors such as the quality of the bearings and magnets used are still of great importance. However, in terms of delivering the true potential of the stepper, it is the controller that can really make a difference.
As an example a simple stepper motor driver will simple convert an input current and voltage into motor torque and speed. Compare this to a comprehensive ‘all in one’ stepper motor driver and controller such as the Zikodrive ZD4 Stepper Motor Controller which has onboard memory, 128 microstepping and full programmability. With the ZD4 Stepper Motor Controller being used it becomes possible to directly control the stepper motor position, its acceleration and deceleration curves, custom startup sequences, the exact speed and torque and to store these settings within the controller. This enables the motor to be completely optimised and opens up a whole new world of potential mechanical performance and applications.
Whereas a brushless DC motor and controller would require careful calibration, timing and the use of encoders and limit switches to rotate a prism 120 degrees, wait a set time and rotate another 120 degrees, with a stepper motor this can be achieved relatively simply because it is possible to measure the exact number of steps required to make this movement and use an intelligent controller to make this movement.
If one considers more complex applications such as robotics or highly accurate dosing equipment then one can appreciate how useful having this level of control would be. By adding a controller capable of microstepping such as the ZD4 Stepper Motor Driver (this offers up to 128 microsteps) it is possible to gain exceptional positional accuracy. Based on a standard 1.8 degree 200 step motor, the ZD4 Driver can move accurately between any of 25600 points of a circle.
Fundamentally, it can therefore be the key advantages of steppers is that they enable the motor to stop and start at any point required with exceptional accuracy. In combination with an intelligent motor controller it is possible to achieve exceptional positional accuracy and performance from a stepper motor that is quite simply unachievable with any other type of motor.