1. What is a DC Motor Torque Calculator?

Definition: This calculator determines the torque produced by a DC motor based on its horsepower and rotational speed (RPM).

Purpose: It helps engineers, technicians, and hobbyists understand motor performance characteristics for proper motor selection and application.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( T \) — Torque (pound-feet)
• \( HP \) — Horsepower
• \( RPM \) — Revolutions per minute
• 5252 — Conversion constant (derived from unit conversions)

Explanation: The formula relates the motor's power output to its rotational speed, showing how torque decreases as RPM increases for a given horsepower.

3. Importance of Torque Calculation

Details: Proper torque calculation ensures the motor can handle the required load without stalling or overheating, and helps in gear ratio selection.

4. Using the Calculator

Tips: Enter the motor's horsepower rating and operating RPM. Both values must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why is 5252 the constant in the formula?
A: It comes from unit conversions (1 HP = 550 ft-lb/sec and 1 minute = 60 seconds) where 550 × 60 / 2π ≈ 5252.

Q2: Does this work for AC motors too?
A: Yes, the formula applies to any rotating machinery, though AC motors have additional factors like power factor.

Q3: What if I know torque but need horsepower?
A: Rearrange the formula: HP = (T × RPM) / 5252.

Q4: Why does torque decrease as RPM increases?
A: For a given power output, the motor must trade off between speed and turning force (torque).

Q5: What's typical torque for small DC motors?
A: Small hobby motors might produce 0.1-1 lb-ft, while industrial motors can produce hundreds of lb-ft.