1. What is a Pulley And Motor Speed Calculator?

Definition: This calculator determines the output RPM of a driven pulley based on the 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)
• \( D1 \) — Drive pulley diameter (inches)
• \( D2 \) — Driven pulley diameter (inches)

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

Q2: What if I need to calculate D1 or D2 instead?
A: Rearrange the formula: \( D1 = \frac{RPM2 \times D2}{RPM1} \) or \( D2 = \frac{RPM1 \times D1}{RPM2} \).

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

Q4: How does this apply to multiple pulley systems?
A: Calculate each stage sequentially, using the output RPM from one pair as the input for the next.

Q5: What about belt slippage?
A: This calculation assumes no slippage. For critical applications, consider a 1-3% slippage factor.