The Ultimate Guide to Electric Servo Motors & Machinery

As technology becomes more complicated, one of the biggest anomalies is the power of the servo motor. Whereas other motors require gallons of fuel and reservoirs of fluids to perform the necessary functions, a servo motor requires none of those things yet it works with great speed and efficiency. Unlike other motors that cause large amounts of noise and are easily prone to heating issues, an electric servo motor will stay cool and remain relatively quiet.

What Is an Electric Servo Motor?

A servo motor is either a rotary actuator or a linear actuator that controls the angling, positioning, speed and acceleration of a piece of machinery. Machines that run on electric servo motors can be activated and controlled via sensors. Whether an application relies on torque or forward momentum, a servo motor will generally meet the demands with greater precision and reliability than other motor types. As such, servo motors are considered the wave of the future in the technological sector.

What is a servo motor in relation to other motors? This can best be answered by comparing the mechanisms of an electric servo motor to the other actuator motor type, the stepper motor.


A servo typically consists of a four to 12-pole brushless motor. The functions of the motor rely on a system of pulse, encoding and feedback mechanisms. In terms of rotational speed and force, servo motors deliver flat and constant torque. An electric servo motor uses only the required current to run and is therefore a lot cooler than the stepper motor. At its peak, the servo motor can produce two to three times the regular torque. As such, servo motors are generally used for higher speed applications of 2,000 rpm or more.


A stepper usually consists of a 50 to 100-pole brushless motor. Unlike the servo, the stepper has no encoder for feedback. Torque is also more limited here, as the stepper is capable of offering a low-speed holding torque that drops at higher speeds. The stepper motor uses more energy at all times, since it draws on full current regardless of whether the motor is running or still. Consequently, the stepper motor also produces more heat than an electric servo motor. The stepper motor is mostly used in applications that only require 2,000 rpm or less.

The Workings of a Servo Motor

For such a small and simple motor, the electric servo is capable of high speeds and efficient productions. As such, manufacturers who haven't yet harnessed the technology will often ask, "How do electric servo motors work?" The workings of a servo motor are defined by the following factors.


Servo motors are run on closed-loop mechanisms that control the motion and final position of given piece of machinery. Not only does the mechanism determine where and how the movements occur, but it also determines when and where the movements stop. Therefore, the motions are easy to predetermine on any application where an electric servo motor is put to use. This applies regardless of whether a factory runs a low- or high-speed application or operates a machine for short or long durations.


A servo motor is typically paired with an encoder for speed and position feedback. This way, communication between the movements and controls are maintained at all times during the course of operations. Servo motor applications provide an advantage in this regard because the velocity and position of a given piece of machinery can be encoded with each usage. This also reduces the chance that a piece of machinery will fall below speed or end up in the wrong position.


A servo motor consists of a motor coupled with a sensor. The sensor is a highly advanced component that picks up signals with utmost accuracy. This makes it possible for either a servo motor CNC machine or piece of broaching equipment to act according to the requirements of a given application. Whether a machine is needed to run with higher or lower velocity, the sensor will instantly pick this up and run things accordingly.


A servo motor requires a high-tech, specially designed controller. Unlike motors that run on fuel, a high-speed servo motor is electronically controlled during each stage of an application. With superior control comes a unique ability to execute processes with utmost precision. When an application must commence, things are up and running with no need for any warm-up. The same is true when things must wrap up, because an electric servo motor can instantly bring an operation to a complete stop.


Servo motors are controlled by an electrical pulse — or pulse width modulation (PWM) — through a control wire. A servo motor receives a minimum and maximum pulse as well as a control rate. This way, any machine that's powered by a servo motor will know the speed and direction at which to move and exactly when to speed up, slow down, turn, angle or come to a halt. It's hard to get this kind of exact precision from machines that lack this kind of pulse activation.

How Do Electric Servo Motors Work in Today's Industrial Sector?

As a technology that first came to light during World War II, the servo motor has come a long way over the past 75 years. Early on, servo motors were used to develop anti-aircraft and radar technology for the Allies. Over the decades, the technology has improved to where machines can be trimmed and fastened with greater speed and precision than would ever be possible with human hands.

Industries that rely on electric servo motors range from makers of aircrafts to suppliers of parts for automobiles and furnishings. In the years ahead, the servo motor will likely facilitate the development of robot technology. As things stand, the following industries currently make heavy use of servo motor applications.

Broaching Equipment

Electric servo motors are ideal for toothed tools that are used in factories for the purpose of cutting, trimming, angling and contouring materials. Whereas human hands are prone to fault and fuel-based machines are less reliable in terms of consistency, servo motors generally deliver a uniform cut with each broaching application.

Whether a given set of items consists of wood, metal or synthetic materials, a servo motor can run the broaching equipment with exact precision. From slab and slot surface broaches to solid and modular internal cuts and trims, broaching is one of the foremost servo motor applications in the industrial sector.

CNC Machinery

For applications that rely on computer numeric control, servo motors are the favored type of motor. A servo motor CNC machine is capable of applying rivets and fastening sections with optimal efficiency, and this allows manufacturers to boost productivity and deliver superior products with far less overhead than would otherwise be possible.

All these assets are due to the reliability of the electric servo motor, which can run rotary and linear applications with exact speed and precision. When it comes to fastening aircraft parts, there's no risk of over or under-fastening, because movements are controlled to their exact end point.


One of the most exciting developments in recent years has been the rapid advancement of robotic technology. Machines are now being programmed to perform actions that 30 years ago or more would have been the stuff of sci-fi movies. Pretty soon, machines could be introduced that will relieve humans of some of the most arduous labors on the planet. These developments have largely occurred in tandem with advances in electric servo motor technology.

When a machine is controlled with a servo motor, artificial arms and legs can be encoded to behave exactly as desired. Whether a robot is used to lift heavy equipment or perform cleaning tasks in toxic, dangerous environments, servo motor manufacturers will be the ones to thank for these developments.

Automated Manufacturing

In industries that depend on high-volume productions, electric servo motors are utilized in a vast range of automation machinery. The benefits here are numerous because servo motors make it possible for machines to perform uniform applications with utmost efficiency along assembly lines.

In the food industry, servo motors can be used to power machines that perform packaging and labeling tasks. When it comes to parts assembly among electronics manufacturers, the electric servo motor makes it possible for products to be assembled with machines that don't use fuel and aren't prone to condensation. Therefore, servo motor applications are among the safest of options in the manufacturing sector.

The Advantages and Benefits of Using a Servo Motor

When it comes to equipment options, a company's foremost concerns should be efficiency and reliability. Those qualities are just two of the many benefits that come with high-speed servo motor applications.

In any given field, manufacturers want to reduce and possibly eliminate the use of fuel, all the while saving on energy costs. Likewise, companies would like to deal with less heat and noise during the processes of a given shift. All these goals are being met by companies that have implemented the use of servo motors in the machines that drive productions and assembly-line tools and equipment.

Water-Based Coolant

Electric servo motors are far less prone to heating than other motor types. For the times when a servo motor does get warm, a water-based coolant is used to keep the motor down to an ideal temperature for any given application. This way, machines that run on servo motors carry less weight or bulk because there's no need for a noisy internal fan system. Therefore, servo motor applications are lighter and less cumbersome in all industries.

Don't Use Oil

If there's one thing most industries would prefer to cut down on, it's the consumption of fuel. Not only do fuel costs inflate overhead and cut into profit margins, but fuel production is also harmful to the environment. One of the greatest things about the electric servo motor us that it doesn't rely on fuel for power. As such, servo motor applications are the most environmentally friendly means of production in today's world.

Electric Is Cheaper

In the world of manufacturing, all decisions are motivated by the wish to boost profit margins. To that end, one of the most effective strategies is to save money on overhead costs. This can be accomplished by adopting technology that costs less to operate but still delivers exceptional results. Servo motor applications are a win/win technology in this regard because they allow companies to spend less on operating costs, yet produce at greater speeds and quantities.

It's Quiet

Since there's less mechanical baggage with servo motor applications, the machines that use this type of motor are generally quieter than machines powered by other means. With a liquid coolant to keep things at ideal temperatures, there's no need for noisy fan blades to wind up each time a machine gets warm. As indicated by the lack of need for oil, there's no grinding of metal parts within the internal mechanisms, and therefore none of the noise that would stem from an auto motor.

More Efficient

Due in part to the more compact and less cumbersome nature of the technology involved, electric servo motors are more efficient than competing motor types. Since the motor requires less internalized processes to simply function, applications are performed at greater speeds with less energy consumption. Thanks to the uniform reliability of servo motor applications, companies that use this technology are less prone to faulty productions and the financial setbacks that occur when things must be redone.

No Hydraulics

When people ask, "How do electric servo motors work?" they're often surprised to learn no hydraulics are involved. Whereas larger motor systems involve numerous functions that each require a separate fluid reservoir, you don't have to worry about the flow of pipes and whether or not it's time to refill. Without the piping associated with hydraulics, machines that use electric servo motors are generally smaller, and this further contributes to the higher efficiency and quietness of such machinery.

With all of these advantages, servo motor repair is relatively simple. Though the technology has yet to be fully embraced throughout the industrialized world, all machines have the capability to be electric driven. In everything from the assembly of automobiles, furniture and electronics to the production of food and apparel, electric servo motors can help companies boost profits and slash overhead while delivering top-quality products with maximum efficiency and little to no downtime.

Contact Colonial Tool Group About Electric Servo Motors

As technologies in broaching, CNC machinery, robotics and manufacturing continue to advance, an increasing number of companies will embrace servo motor applications. For many manufacturers, the electric servo motor will lead to boosted productions, heightened profiles and an increased presence on the national and international commercial landscape. With so many opportunities up for grabs, the time to harness the potential of servo motors is now, not later.

At Colonial Tool Group, our mission is to help you streamline the processes associated with CNC machinery and broaching tools. To learn more about our machines and services, contact our experts today.