1. What is the Pulley Size Equation?

The pulley size equation calculates the required pulley size to achieve a specific output RPM based on the input RPM and driven pulley size. This is essential for proper mechanical system design and power transmission.

2. How Does the Calculator Work?

The calculator uses the pulley size equation:

Where:

• Input RPM — Rotational speed of the driving pulley (rev/min)
• Output RPM — Desired rotational speed of the driven pulley (rev/min)
• Driven Size — Diameter of the driven pulley (inches)

Explanation: The equation maintains the velocity ratio between the two pulleys to achieve the desired speed change.

3. Importance of Pulley Size Calculation

Details: Correct pulley sizing ensures proper speed transmission, prevents belt slippage, and maintains system efficiency in mechanical drives.

4. Using the Calculator

Tips: Enter input RPM (speed of driving pulley), output RPM (desired speed), and driven pulley size. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Can I use this for belt length calculation?
A: No, this only calculates pulley size. Belt length depends on center distance and both pulley sizes.

Q2: Does this work for V-belts and flat belts?
A: Yes, the basic speed ratio calculation applies to all belt types, though actual selection may require additional considerations.

Q3: What if I know the pulley size and need RPM?
A: Rearrange the formula: Output RPM = (Input RPM × Driven Size) / Driving Pulley Size

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

Q5: Can I use metric units?
A: The calculator uses inches, but you can use any consistent unit (mm, cm) as long as all sizes are in the same unit.