1. What is a Pulley RPM Calculator?

Definition: This calculator determines the output RPM of a driven pulley based on input RPM and pulley diameters.

Purpose: It helps mechanical engineers, technicians, and DIYers design and troubleshoot belt-driven systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( RPM2 \) — Output RPM (driven pulley)
• \( RPM1 \) — Input RPM (drive pulley)
• \( D1 \) — Diameter of drive pulley (inches)
• \( D2 \) — Diameter of driven pulley (inches)

Explanation: The output speed is inversely proportional to the ratio of pulley diameters.

3. Importance of Pulley RPM Calculation

Details: Proper RPM calculation ensures equipment operates at designed speeds, prevents belt slippage, and maintains optimal performance.

4. Using the Calculator

Tips: Enter the input RPM, drive pulley diameter, and driven pulley diameter. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Can I calculate pulley size from RPM?
A: Yes, rearrange the formula: \( D1 = \frac{RPM2 \times D2}{RPM1} \)

Q2: Does belt thickness affect the calculation?
A: For precise calculations, use pitch diameter (accounting for belt thickness) rather than outer diameter.

Q3: What if pulleys are different types?
A: The formula works for any pulley combination (V-belt, flat belt, timing belt) as long as diameters are measured consistently.

Q4: How does multiple pulleys affect RPM?
A: For multiple stages, calculate each pair sequentially (output of first becomes input of second).

Q5: What's a typical RPM range for belt drives?
A: Most belt drives operate between 500-3600 RPM, but consult manufacturer specifications for your specific system.