FPV Drone Motor Torque

Motor torque is the moment that causes an object to rotate. ForFPV drone systems, torque determines the ability of drone motors to drive drone propellers. The greater the torque, the stronger the motor’s ability to accelerate drone propellers, and the faster the flight response—critical for aggressive FPV flying and stable cruising.

Factors Affecting Torque

1. Stator Size: A larger stator can accommodate more copper windings, generating a stronger magnetic field to enhance torque—ideal for matching largedrone propellers and heavy drone frame setups.
2. Magnet Strength: N52 magnets provide a stronger magnetic field than N42 magnets, directly boosting torque output. UFOUAV uses high-grade N52 magnets in its drone motors to ensure superior torque performance.
3. Number of Winding Turns: More winding turns produce greater torque, but they also reduce the KV value. This balance is carefully optimized in UFOUAV uav motor designs for different drone components and flight needs.
4. Current Magnitude: Torque is proportional to current—more current generates greater torque. UFOUAV drone motors are engineered to handle stable current loads, ensuring consistent torque during flight.

Torque Calculation Formula

Torque (T) = Kt × I

Where Kt is the torque constant (unit: N·m/A), and I is the current (unit: A).

Relationship Between Torque Constant (Kt) and KV Value

The torque constant Kt is inversely proportional to the KV value, following the formula: Kt = 1 / (KV × 1.356)

This means: the lower the KV value, the larger the torque constant, and the greater the torque generated under the same current—essential knowledge for matching drone motors to your FPV drone and drone frame.

Advantages of High Torque

• Fast acceleration and deceleration capabilities, perfect for aggressive FPV freestyle and racing.
• Better hover stability, even in windy conditions, protecting your drone components from unnecessary stress.
• Stronger wind resistance, ensuring reliable flight in complex outdoor environments.
• Suitable for largedrone propellers, ideal for long-range FPV drone builds with larger drone frame sizes.
• More suitable for aggressive flight styles, providing the responsiveness needed for FPV racing maneuvers.

KV Value and Torque Constant

KV value (RPM/V) is defined as the theoretical rotational speed per volt under no-load conditions. It is a key indicator of drone motors and uav motor performance, directly affecting motor speed and power output—critical for matching drone propellers and drone frame configurations.

KV Value Calculation

Rotational Speed (RPM) = KV × Voltage (V)

For example, the theoretical maximum speed of a 1700KV uav motor with a 6S battery (22.2V) is: 1700 × 22.2 = 37,740 RPM—ideal for 5-inch FPV drone racing setups with compatible drone propellers.

Relationship Between KV Value and Torque Constant (Kt)

As mentioned earlier, the KV value is inversely proportional to the torque constant (Kt): Kt = 1 / (KV × 1.356)

This translates to:

• High KV Motors (e.g., 3000KV): Have a low torque constant, suitable for high-speed, low-torque applications—perfect for small drone propellers and compact drone frame setups like 3-inch FPV drone.
• Low KV Motors (e.g., 1300KV): Have a high torque constant, suitable for low-speed, high-torque applications—ideal for large drone propellers and long-range FPV drone with larger drone frame.

KV Value Selection Guide

Common Misconceptions About KV Value Selection

1. “The higher the KV value, the better”: High KV values do provide higher speeds, but they also lead to lower efficiency and more heat generation—potentially damaging drone components over time. UFOUAV recommends matching KV values to yourdrone frame and drone propellers.
2. “Low KV values save power”: Low KV values are more efficient at high voltages, but they require larger drone propellers to maximize performance. Ensure compatibility with your drone frame before selecting a low KV uav motor.
3. “Choose any KV value”: KV values must match battery voltage and drone propellers size. Mismatched KV values can reduce flight time, damage drone motors, and affect overall FPV drone performance. UFOUAV’s drone motors are pre-tuned to match common drone components setups.

UFOUAV offers a full range of drone motors and uav motor options, with optimized torque and KV values for every FPV drone build—from 3-inch tiny whoops to 7-inch long-range drones. Our motors are designed to work seamlessly with all drone components, drone propellers, and drone frame sizes, ensuring reliable performance and optimal flight experience.

Read more at Custom Industrial Drone Solutions, UAV Payload Manufacturer & Supplier|UFOUAV