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What is the size of a 120MM Brushless Motor?

Nov 04, 2025

Tom Green
Tom Green
Tom is a senior researcher at Duowei Electric, focusing on the development of sustainable materials for electrical applications. His work contributes to the company's commitment to avoiding conflict minerals.

When it comes to the world of brushless motors, the 120MM brushless motor stands out as a powerful and versatile option. As a supplier of 120MM brushless motors, I am often asked about the size and its implications. In this blog post, I will delve into the details of the size of a 120MM brushless motor, exploring its dimensions, performance characteristics, and applications.

Understanding the 120MM Specification

The "120MM" in the name of the brushless motor refers to the outer diameter of the motor's stator. The stator is the stationary part of the motor that contains the coils of wire. A larger stator diameter generally allows for more copper windings, which can lead to increased power output and torque. However, the size of the motor is not solely determined by the stator diameter; other factors such as the length of the motor, the number of poles, and the type of magnets used also play important roles.

Physical Dimensions

The physical dimensions of a 120MM brushless motor can vary depending on the specific design and manufacturer. In general, a 120MM brushless motor will have an outer diameter of approximately 120 millimeters, as the name suggests. The length of the motor can range from a few centimeters to over a dozen centimeters, depending on the intended application and the amount of power required.

For example, a 120MM brushless motor designed for use in a small electric vehicle might be relatively short and compact, with a length of around 50 - 70 millimeters. On the other hand, a 120MM brushless motor used in an industrial application, such as a conveyor belt or a large robotic arm, might be longer, with a length of 100 millimeters or more.

Performance Characteristics

The size of a 120MM brushless motor has a significant impact on its performance characteristics. As mentioned earlier, a larger stator diameter allows for more copper windings, which can increase the motor's power output and torque. This makes 120MM brushless motors well - suited for applications that require high levels of power and torque, such as electric vehicles, industrial machinery, and large drones.

In addition to power and torque, the size of the motor also affects its efficiency and speed. A larger motor can generally dissipate heat more effectively, which can improve its efficiency and allow it to operate at higher speeds without overheating. However, it's important to note that the actual performance of a 120MM brushless motor will also depend on other factors, such as the quality of the materials used, the design of the motor's controller, and the operating conditions.

Applications

The 120MM brushless motor's combination of power, torque, and efficiency makes it suitable for a wide range of applications. Here are some of the most common applications:

Electric Vehicles

In the electric vehicle industry, 120MM brushless motors are often used in electric scooters, electric bicycles, and small electric cars. These motors provide the high torque needed for acceleration and the efficiency required for long - range operation.

Industrial Machinery

Industrial machinery such as conveyor belts, pumps, and robotic arms often require high - power motors to operate effectively. 120MM brushless motors can provide the necessary power and torque, while their compact size allows them to be easily integrated into existing machinery.

Drones

Large drones, especially those used for commercial applications such as aerial photography and surveying, require powerful motors to lift heavy payloads. 120MM brushless motors can provide the high thrust needed for takeoff and stable flight.

Comparison with Other Brushless Motors

It's useful to compare the 120MM brushless motor with other types of brushless motors to better understand its advantages and limitations. For example, the 83MM Brushless Motor is smaller in size, which makes it more suitable for applications where space is limited. However, it generally has lower power and torque compared to the 120MM brushless motor.

On the other hand, larger brushless motors can provide even more power and torque, but they are also heavier and more expensive. The 120MM brushless motor strikes a good balance between size, power, and cost, making it a popular choice for many applications.

Specialized Variants

There are also specialized variants of the 120MM brushless motor that are designed to meet specific requirements. For example, the 48V 300W BLDC Motor is a type of 120MM brushless motor that operates at a voltage of 48 volts and has a power output of 300 watts. This type of motor is often used in applications where a specific power and voltage combination is required.

Another specialized variant is the 48V 3000RPM Brushless DC Motor. This motor is designed to operate at a speed of 3000 revolutions per minute, making it suitable for applications that require a constant and high - speed operation.

Customization Options

As a supplier of 120MM brushless motors, we understand that different customers have different requirements. That's why we offer a range of customization options for our 120MM brushless motors. We can customize the motor's length, power output, voltage, and speed to meet the specific needs of your application. Whether you need a motor for a small electric vehicle or a large industrial machine, we can work with you to develop the perfect solution.

48V 300W BLDC Motor83MM Brushless Motor

Conclusion

In conclusion, the size of a 120MM brushless motor, with its 120 - millimeter stator diameter, offers a unique combination of power, torque, and efficiency. Its physical dimensions can vary, but it generally provides a good balance between size and performance, making it suitable for a wide range of applications. Whether you're in the electric vehicle industry, industrial machinery, or the drone market, a 120MM brushless motor could be the ideal choice for your needs.

If you're interested in learning more about our 120MM brushless motors or have specific requirements for your application, we encourage you to reach out to us for a detailed discussion. Our team of experts is ready to assist you in finding the perfect motor solution for your project.

References

  • "Brushless DC Motors: Theory, Design, and Application" by Ned Mohan
  • "Electric Motors and Drives: Fundamentals, Types, and Applications" by Austin Hughes and Bill Drury

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