Stepper motor technology greatly simplifies machine design. They offer nearly servo-like positioning performance—without the need for complex feedback devices or a closed-loop control system. For example, in an open-loop system, such as bottles being directed one way or another by a lane diverter, a stepper can offer the required motion that delivers optimal results and cost savings. When it comes to precise motion, stepper motors have a distinct advantage over their servo counterparts.
Easier Setup, Lower Cost
Stepper motors are easier to set up than a typical servo motor. There is no tuning required, unlike alternatives, and they are simpler to manage during the project design phase. Normally, stepper motors are sized for peak torque along with a safety factor that ranges from 50 to 100 percent. Other motor technologies may involve more complicated calculations during the design phase, bringing acceleration, deceleration, slew rate, RMS torque, dwell time and other factors into consideration.
Benefit of Microstepping
Microstepping technology has eased the decision to go with a stepper motor when a smooth motion is desired. Before microstepping technology, stepper motors moved at 1.8 degrees or 200 steps per revolution. They went from having no movement to an immediate speed of 200 steps per second (60 RPM) or vice versa, which often resulted in jerky starts and stops.
With microstepping technology, the standard 1.8 degrees is subdivided by a factor of as much as 250. The result is a smoother motion as well as the increased ability to move through and within the low-end resonance speed region. Microstepping technology also allows more precise and repeatable positioning when used with an encoder for auto-correction. That precision is repeatable if the motion is always in the same direction and if the system is not powered down.
NOTE: If both situations are not the case, then a stepper motor will need the encoder feedback for confirmation and to correct positioning.
Selecting the Right Stepper Motor
The right stepper motor must produce the necessary load torque, speed, motion profile requirements, physical envelope, and voltage. The fastest and most reliable way to determine these needs is with our motor sizing tool. This tool calculates motor load points and then analyzes the load and motion profile to generate a list of possible motor matches from the stepper motor database. By determining the stepper motor performance curve, temperature profile (an output of the sizing tool), and motor operating voltage, the sizing tool will highlight the best stepper motor option.