1. What is Brushless Motor RPM?

Brushless motor RPM (Revolutions Per Minute) is the rotational speed of the motor's output shaft. It's determined by the input voltage, motor's Kv rating, and any gear reduction applied.

2. How Does the Calculator Work?

The calculator uses the brushless motor RPM formula:

Where:

• \( Voltage \) — Input voltage to the motor (V)
• \( Kv \) — Motor's velocity constant (RPM per volt)
• \( Gear\ Ratio \) — Ratio of motor speed to output speed (e.g., 3:1)

Explanation: The Kv rating indicates how many RPM the motor will turn per volt with no load. The actual RPM under load will be slightly lower due to efficiency losses.

3. Importance of RPM Calculation

Details: Knowing the expected RPM helps in selecting the right motor and gearing for your application, whether it's for drones, RC vehicles, or industrial applications.

4. Using the Calculator

Tips: Enter the battery voltage, motor Kv rating, and gear ratio. If no gear reduction is used, enter 1 for gear ratio. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is Kv rating?
A: Kv is the motor's velocity constant, representing RPM per volt with no load. A 1000Kv motor will spin at approximately 1000 RPM per volt with no load.

Q2: Why is actual RPM lower than calculated?
A: Real-world RPM is affected by load, efficiency losses, battery voltage drop under load, and other factors.

Q3: How does gear ratio affect RPM?
A: Higher gear ratios reduce output RPM while increasing torque. A 2:1 gear ratio halves the RPM but doubles the torque.

Q4: What's a typical Kv range for brushless motors?
A: Kv ratings vary widely from <100 for large motors to >5000 for small, high-speed motors.

Q5: Can I use this for brushed motors?
A: The calculation works similarly, but brushed motors typically have lower Kv ratings and different efficiency characteristics.