1. What is a Two Pulley Speed 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 DIY enthusiasts design and troubleshoot pulley 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 between two pulleys is inversely proportional to their diameter ratio.

3. Importance of Pulley Speed Calculation

Details: Proper pulley speed calculation ensures optimal machine performance, prevents belt slippage, and maintains desired operational 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: Does belt thickness affect the calculation?
A: For precise calculations, use the pulley's pitch diameter (accounting for belt thickness), but for most applications, outer diameter is sufficient.

Q2: What if I have more than two pulleys?
A: Calculate sequentially - the output of one pulley becomes the input for the next.

Q3: How does this relate to torque?
A: While this calculates speed, remember that torque changes inversely with speed in a pulley system.

Q4: What about belt length?
A: This calculator doesn't determine belt length, only speed ratio. Use a separate belt length calculator for that.

Q5: Can I use metric units?
A: The calculator works with any consistent units (all inches or all mm), but results will be in the same units as input.