1. What is a Head Speed Calculator for RC Helicopters?

Definition: This calculator determines the head speed (blade tip speed) of an RC helicopter based on motor RPM and rotor diameter.

Purpose: It helps RC enthusiasts optimize their helicopter's performance by calculating the critical head speed parameter.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HS \) — Head speed (meters/second)
• \( RPM \) — Motor revolutions per minute
• \( Diameter \) — Rotor diameter (meters)
• \( \pi \) — Mathematical constant Pi (~3.1416)

Explanation: The formula calculates how fast the rotor blade tips are moving through the air, which is crucial for lift and performance.

3. Importance of Head Speed Calculation

Details: Proper head speed ensures optimal lift, stability, and prevents damage from excessive speeds. Different flight styles (3D, sport, scale) require different head speeds.

4. Using the Calculator

Tips: Enter your motor's RPM (from specs or governor setting) and measure your main rotor diameter in meters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical head speed for RC helicopters?
A: Most RC helicopters operate between 1500-3000 RPM, resulting in head speeds of 100-250 m/s depending on rotor size.

Q2: How do I measure rotor diameter?
A: Measure from one blade tip to the other (full rotor disc diameter) in meters.

Q3: Why is head speed important?
A: It affects lift, responsiveness, and blade stress. Too low = poor performance, too high = dangerous stress.

Q4: How does gear ratio affect this calculation?
A: Use the actual rotor RPM (motor RPM divided by gear ratio) if your system has gear reduction.

Q5: What units should I use?
A: RPM must be in revolutions per minute, diameter in meters, result is in meters/second.