1. What is the kV to RPM Conversion?

The kV to RPM conversion calculates the rotational speed of an electric motor based on its kV rating (RPM per volt) and the applied voltage. This is commonly used in brushless DC motors for applications like drones, RC vehicles, and industrial equipment.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( kV \) — Motor constant (revolutions per minute per volt)
• \( V \) — Applied voltage (volts)

Explanation: The kV rating indicates how many RPM the motor will turn per volt applied (with no load). Multiplying by voltage gives the theoretical maximum RPM.

3. Importance of RPM Calculation

Details: Knowing the expected RPM helps in selecting the right motor for an application, predicting performance, and ensuring components operate within safe speed limits.

4. Using the Calculator

Tips: Enter the motor's kV rating (found in specifications) and the voltage you plan to apply. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Is this the actual RPM under load?
A: No, this is the theoretical no-load RPM. Actual RPM under load will be lower due to factors like efficiency and torque requirements.

Q2: How accurate is this calculation?
A: It's accurate for no-load conditions. For loaded conditions, expect 70-90% of calculated RPM depending on motor efficiency and load.

Q3: What affects a motor's kV rating?
A: kV is determined by motor design - number of windings, magnets, and overall construction. Lower kV means more torque at lower RPM.

Q4: Can I use this for brushed motors?
A: Brushed motors don't typically use kV ratings. This calculation is specific to brushless motors.

Q5: What's a typical kV range for drone motors?
A: Small drone motors range from about 1000-3000 kV, while larger motors might be 100-500 kV.