1. What is a Pulley Ratio Calculator?

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

Purpose: It helps mechanics, engineers, and DIY enthusiasts design and troubleshoot pulley systems for machinery and equipment.

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 speed ratio is inversely proportional to the diameter ratio of the pulleys.

3. Importance of Pulley Ratio Calculation

Details: Proper pulley ratio calculation ensures optimal machine performance, prevents belt slippage, and maintains desired speed output.

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: What happens if I use a larger driven pulley?
A: A larger driven pulley will decrease the output RPM compared to the input RPM.

Q2: Can I use this for belt length calculation?
A: No, this only calculates speed ratio. You'll need a separate calculator for belt length.

Q3: Does this work for multiple pulley systems?
A: For multiple pulleys, you would calculate the ratio for each stage sequentially.

Q4: How accurate is this calculation?
A: It's theoretically accurate, but real-world factors like belt slip can affect actual performance.

Q5: What if my pulleys are different types?
A: The calculation works the same as long as you use the effective pitch diameters.