Drone motors are critical in the performance of modern unmanned aerial vehicles (UAVs) and drones. They generate the lift, precise control, and stability required for complex maneuvers, from smooth aerial cinematography to high-speed racing.

Then, which motor is used in drones? While several motor types exist, the overwhelming industry standard for performance, industrial, and high-end consumer drones is the brushless DC (BLDC) motor. Meanwhile, cheaper, smaller, or toy-grade models often still utilize the simpler brushed DC motor.

Types of Motors Used in Drones

1. Brushless DC (BLDC) Drone Motors

BLDC motors are by far the most common motors in consumer, racing, commercial, and professional drones. They operate without physical brushes; instead, an electronic speed controller (ESC) precisely manages the current to the stationary windings, creating a rotating magnetic field that turns the permanent magnet rotor. This design eliminates the friction and wear associated with brushed motors.

The advantages of the brushless technology are substantial:

| High Efficiency: BLDC motors convert over 90% of electrical energy into mechanical power, significantly extending flight times compared to brushed alternatives.

| Exceptional Durability: Without brushes to wear out, BLDC motors offer a much longer lifespan, often lasting thousands of hours.

| High Power Density: They deliver substantial torque and power for their size and weight, enabling drones to carry heavier payloads like professional cameras or survey equipment.

| Precise Control: They allow for exact speed and position management, which is crucial for stable hovering and smooth flight.

Product shown: BLDC Drone Motors

2. Brushed DC Drone Motors

Brushed DC motors are the simpler technology. They use physical carbon brushes and a commutator to supply power to the motor windings on the rotor. They are most cost-effective and typically found in:

| Entry-level and toy-grade drones

| Miniature or micro-drones where cost is the primary driver

They come with significant limitations, including lower efficiency (leading to shorter flight times), mechanical brush wear that limits their operational life, and greater electromagnetic interference.

3. Coreless Drone Motors

Coreless motors feature a unique ironless rotor winding that resembles a self-supporting basket or cup, rather than a traditional iron-core armature. This innovative construction provides several key benefits:

| Rapid Acceleration: The drastically reduced rotor inertia (due to reduced weight) allows for almost instantaneous changes in speed.

| Smooth Operation: They deliver exceptionally uniform torque with minimal cogging.

| High Power-to-Weight Ratio: Their lightweight design is ideal for the smallest aerial platforms.

These characteristics make them the motor of choice for ultra-lightweight applications, including miniature indoor drones and quadcopters.

How to Choose Drone Motors: Key Parameters

To select the right motors used in drones, you need to consider the following:

1. KV Rating Explained (RPM per Volt)

The KV rating represents the drone motor’s velocity constant, specifically the number of revolutions per minute (RPM) the motor will achieve per volt applied, under no load.

| High KV (e.g., 2200 KV): Spins faster but with less torque. Ideal for small propellers, high-speed, agile racing drones, or lightweight builds.

| Low KV (e.g., 800 KV): Spins slower but generates more torque. Ideal for larger propellers, heavy-lift, cinematic, or long-endurance drones.

The theoretical RPM is calculated as: RPM = KV × Voltage.

2. Motor Thrust and Relation to Drone Weight

Motor thrust is the lifting force generated by the motor/propeller combination. The most important calculation is the thrust-to-weight ratio (TWR). For stable, controlled flight, the total maximum thrust of all motors must significantly exceed the drone’s total takeoff weight (including battery and payload).

| Minimum TWR: You generally need a ratio of at least 2:1 (thrust is twice the weight) for basic flight.

| Performance Drones: Racing or highly acrobatic drones may aim for higher ratios, such as 5:1, for aggressive acceleration and agility.

3. Torque Characteristics for Different Drone Applications

Torque is the rotational force produced by the motor. It is the motor's ability to spin the propeller against air resistance.

| High Torque: Needed to drive large, high-pitched propellers, especially on heavy-lift platforms (e.g., industrial drones). High torque is typically associated with low KV motors.

| Low Torque: Sufficient for spinning small, light propellers at very high speeds, which is characteristic of high KV motors used in racing.

4. Propeller Size Compatibility with Motors

Your motor, propeller, and battery must work in harmony. A mismatch can lead to inefficient performance or even motor damage.

A low KV motor paired with a large propeller will generate excellent thrust and efficiency for a slow-flying photography platform. Conversely, a high KV motor paired with a small propeller creates the high-speed thrust needed for a racing drone.

5. Efficiency, Noise, and Durability Factors

For commercial and professional applications, longevity and operational factors are crucial:

| Efficiency: BLDC motors are much more efficient, converting more battery power into lift, which directly translates to longer flight times.

| Durability: The lack of friction-creating components in BLDC motors ensures a longer service life and minimal maintenance.

| Noise: Brushless motors are significantly quieter, which is critical for surveillance or sensitive aerial photography applications.

Trust Power Motor for Your Drone Motor Solutions

Established in 2001, Power Motor has rich expertise in micro motors, especially custom motor solutions. We can design motors to your specs—you tell us your drone weight, prop size, flight style, and battery setup, and we can tailor KV, stator size, torque, and efficiency accordingly. 

Our commitment to high-performance motors means each unit is built for durability, using quality components and undergoing rigorous testing, so you don’t need to worry about failure mid-flight.

Picture shown: 24V Drone Motor

Conclusion

Choosing the right motor is one of the most important decisions in drone design, and BLDC drone motors dominate the market so far. By carefully considering parameters like KV rating, thrust, and torque, you can ensure your drone achieves its maximum potential.

For demanding applications that require a motor perfectly tailored to unique specifications, Power Motor helps by taking full advantage of our motor expertise. If you need any support, contact Power Motor today to discuss your project-specific requirements!