1. What is the kV to RPM Formula?

The kV to RPM formula calculates the rotational speed of an electric motor based on its kV rating (RPM per volt) and the applied voltage. This is essential for understanding motor performance in various applications.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( kV \) — Motor constant (revolutions per minute per volt)
• \( Voltage \) — Applied voltage to the motor

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 RPM helps in selecting the right motor for applications like drones, RC vehicles, and industrial machinery where specific speed requirements exist.

4. Using the Calculator

Tips: Enter the motor's kV rating (found in specifications) and the voltage you plan to use. 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 load torque.

Q2: 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 but lower top speed.

Q3: Can I use this for brushless DC motors?
A: Yes, this formula is primarily used for brushless DC motors commonly found in RC and drone applications.

Q4: How does battery voltage affect RPM?
A: Higher voltage increases RPM proportionally to the kV rating. A 1000kV motor on 12V spins at 12,000 RPM, on 24V at 24,000 RPM.

Q5: What's the relationship between kV and torque?
A: Generally, lower kV motors produce more torque at lower RPMs, while higher kV motors spin faster but with less torque.