1. What is a Pulley Speed Calculator RPM?

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 troubleshoot pulley systems in machinery and equipment.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( RPM2 \) — Output RPM of driven pulley
• \( RPM1 \) — Input RPM of 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 rotate slower than the drive pulley.

3. Importance of Pulley Speed Calculation

Details: Proper pulley speed calculation ensures optimal machine performance, prevents equipment damage, and helps achieve desired operational speeds.

4. Using the Calculator

Tips: Enter the input RPM, drive pulley diameter, and driven pulley diameter. All values must be > 0. The calculator will compute the output RPM.

5. Frequently Asked Questions (FAQ)

Q1: What happens if D2 is larger than D1?
A: The output RPM will be lower than the input RPM (speed reduction).

Q2: What if D2 is smaller than D1?
A: The output RPM will be higher than the input RPM (speed increase).

Q3: Does belt thickness affect the calculation?
A: For precise calculations, use the pitch diameter (center of belt thickness) rather than outer diameter.

Q4: Can I use this for multiple pulley systems?
A: For multiple pulleys, calculate each stage sequentially from driver to driven.

Q5: How does this relate to torque?
A: As RPM decreases, torque increases proportionally (and vice versa), maintaining constant power.