1. What is Brushless Motor RPM?

The RPM (Revolutions Per Minute) of a brushless motor indicates how fast the motor's shaft rotates. For Yamaha brushless motors, this is calculated based on the input voltage, motor's Kv rating, and gear ratio.

2. How Does the Calculator Work?

The calculator uses the RPM formula:

Where:

• \( Voltage \) — Input voltage to the motor (V)
• \( Kv \) — Motor velocity constant (RPM per volt)
• \( Gear\ Ratio \) — Ratio between motor and output shaft

Explanation: The Kv rating indicates how many RPM the motor will turn per volt with no load. The actual RPM under load is affected by the gear ratio.

3. Importance of RPM Calculation

Details: Knowing the motor RPM is crucial for proper motor selection, performance tuning, and ensuring the motor operates within its optimal range for efficiency and longevity.

4. Using the Calculator

Tips: Enter voltage in volts, Kv in RPM per volt, and gear ratio as a number (e.g., 3.5:1 ratio is entered as 3.5). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is Kv rating in brushless motors?
A: Kv is the motor velocity constant that indicates how many RPM the motor will turn per volt with no load. A higher Kv means higher RPM but lower torque.

Q2: How does gear ratio affect RPM?
A: The gear ratio reduces the motor RPM at the output shaft while increasing torque. A higher gear ratio means lower output RPM but more torque.

Q3: What are typical Kv values for Yamaha brushless motors?
A: Yamaha brushless motors typically range from 500-2000 Kv, with lower Kv for higher torque applications and higher Kv for speed applications.

Q4: Why is my actual RPM lower than calculated?
A: The calculation shows theoretical no-load RPM. Actual RPM will be lower due to load, friction, and efficiency losses in the system.

Q5: Can I use this for other brushless motors?
A: Yes, this formula works for any brushless motor, though Yamaha motors have specific performance characteristics at different Kv ratings.