1. What is a Pulley Speed Reduction 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 mechanical engineers, technicians, and DIYers design and analyze 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 speed ratio is inversely proportional to the pulley diameter ratio. A larger driven pulley will reduce speed.

3. Importance of Pulley Speed Calculation

Details: Proper speed calculation ensures optimal machine performance, prevents belt slippage, and helps select appropriate motor speeds.

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 D2 is smaller than D1?
A: The output RPM will increase (speed multiplication rather than reduction).

Q2: Does this work for belt-driven and chain-driven systems?
A: Yes, the same principle applies to both belt and chain drives.

Q3: How does pulley groove depth affect the calculation?
A: For V-belts, use the pitch diameter (approximately the outer diameter minus belt thickness).

Q4: Can I use this for multi-pulley systems?
A: For multiple stages, calculate each reduction sequentially.

Q5: What's the typical RPM range for belt-driven systems?
A: Most systems operate between 500-3000 RPM, but consult manufacturer specs for your specific application.