A stepper motor can help give your project precise positioning

When building a machine or working on a task that necessitates precision, the type of motor you choose could greatly impact your work. When deciding on a motor to best suit your project, careful consideration should be given to the makeup, function, and power needed to drive your plan. Here at Leading Edge Industrial, we utilize stepper motors and drivers on our Computer Numeric Control (CNC) machines when completing assignments. Excellent in areas of accuracy and reliability, the stepper motor is explained in detail below and should be considered when completing projects requiring stability and precise positioning.

What is a stepper motor?

To decide if a stepper motor is right for your project, you must first possess a basic understanding of the motor’s function. A stepper motor is essentially a DC motor (a motor that transforms electrical power into a current, which is then altered into a mechanical rotation), yet it moves in distinct steps. By having the ability to convert sequences of input pulses into exact shaft movements, the stepper motor is valued in projects that require high torque at low speeds and the ability to hold positions without fluctuating.

How Does a Stepper Motor Function?

Electromagnetic pulses help turn the rotor

Though the construction of a stepper motor may seem complex, the basic design is easy to understand. The innermost working of a stepper motor is called a rotor. The rotor is comprised of two discs; one of which is a magnetic north pole and the other is a magnetic south pole. When the discs are placed back-to-back, the teeth on each disc alternate, meaning a segment of north and south pole teeth intertwine.

Another important element called a stator exists within the stepper motor and is wrapped around the edge of the rotor. The stator is composed of four electromagnets which give charge to the teeth on the discs in the rotor. The electromagnets in the stator generally function as pairs, with the opposing magnets firing together to create a north pole, followed by the magnets located at right angles also working together. These electromagnetic charges, in turn, pull the teeth within the rotor: as one of the teeth is pulled toward the north pole, the other tooth is pulled toward the south pole. This action successfully pulls the rotor around by one step. The electromagnetic pulses continue, and the rotor performs the same actions until the pulses stop.  

What is a Stepper Motor Used For?

 A stepper motor is great for medical machinery

Stepper motors can prove extremely useful when used with machines in the medical and security industries, as well as with consumer electronics and most importantly, industrial machinery. Stepper motors excel when positioned in projects that require extreme precision. Because stepper motors rely on pulses to rotate, a machinist is able to control the precise amount of steps a motor will turn, which is especially useful with CNC machines. A stepper motor also excels in processes that necessitate precise speed control, because the pulses within the stator are uniform and will move accordingly. Finally, stepper motors are adept at providing maximum amounts of torque when used at low speeds, because the current has ample time to pass through the coils.  

What are the Unique Benefits of a Stepper Motor, Not Found in a Servo Motor?

Servo motors are great when used in projects that require more power, such as robotic operations or when used with complex conveyor belts. These motors are also adept at providing high torque with high speeds, as well as supplying high-efficiency marks. In addition, servo motors are not affected by resonance—which translates into quieter machinery and no damages due to vibratory imbalances. Though servo motors are extremely useful, are there certain situations in which a stepper motor can outperform a servo motor? The simple answer is yes.

When comparing prices, a stepper motor is highly cost-efficient, proving to be more budget-friendly than a generally expensive servo motor. A stepper motor also provides high torque while functioning at low speeds, which allows the motor to quickly change its position from stationery to dynamic. A stepper motor is also stable when at rest and rarely loses steps—important when completing projects that require accuracy in positioning. With the ability to run on either a closed or open loop system, stepper motors can either harness feedback or simply follow an input command. The last big benefit that a stepper motor holds over a servo motor is an increased number of north and south magnetic poles, which transfers into increased accuracy and precision in a project.

What Should You Consider When Choosing a Stepper Motor?

When picking a stepper motor, careful consideration should be given to the project at hand. If a tight budget plays a major role in the type of motor that can be used, stepper motors are usually a more cost-efficient choice. Attention should also be given to the amount of precision a project requires and the amount of speed that is needed, with stepper motors being most valuable for tasks requiring increased precision and lower acceleration. Special attention should also be given to the amount of torque a task mandates. Stepper motors can be beneficial to a project that necessitates high torque power at lower speeds. At Leading Edge Industrial, we understand that choosing the right motor can be a confusing task. With knowledgeable technicians and years of experience, we would be happy to answer any questions you may have concerning a project.

Sources: https://learn.adafruit.com/all-about-stepper-motors/what-is-a-stepper-motor https://www.imagesco.com/articles/picstepper/02.html