1. What is a Stepper Motor Sizing Calculator?

Definition: This calculator estimates the required torque for a stepper motor based on system inertia, acceleration, and load characteristics.

Purpose: It helps engineers and designers properly size stepper motors for mechanical systems to ensure reliable operation.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( T \) — Total required torque (Nm)
• \( J \) — Moment of inertia (kg·m²)
• \( \alpha \) — Angular acceleration (rad/s²)
• \( T_{friction} \) — Friction torque (Nm)
• \( T_{load} \) — External load torque (Nm)

Explanation: The torque has three components: acceleration torque (inertia × acceleration), friction torque, and load torque.

3. Importance of Proper Motor Sizing

Details: Correct motor sizing prevents stalling, ensures precise positioning, and extends motor life by preventing overheating.

4. Using the Calculator

Tips: Enter the moment of inertia, angular acceleration, friction torque (default 0.1 Nm), and load torque (default 0.5 Nm). All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine moment of inertia?
A: Calculate for each rotating component using J = mr² for point masses or standard formulas for geometric shapes.

Q2: What's a typical angular acceleration value?
A: Common values range from 10-100 rad/s² depending on required speed and positioning time.

Q3: How do I measure friction torque?
A: Use a torque wrench to rotate the unloaded system, or estimate based on bearing specifications.

Q4: Should I add a safety factor?
A: Yes, multiply the calculated torque by 1.5-2× to account for variations and ensure reliable operation.

Q5: What if my system has gearing?
A: Account for gear ratio in inertia (J = J_motor + J_load/N²) and torque (T_load = T_applied/N).