1. What is True Position with MMC?

True Position with MMC (Maximum Material Condition) is a GD&T (Geometric Dimensioning and Tolerancing) calculation that accounts for the bonus tolerance available when a feature is at its maximum material condition. It provides additional tolerance when the actual size of a feature deviates from its MMC size.

2. How Does the Calculator Work?

The calculator uses the True Position with MMC formula:

Where:

• \( TP \) — True Position tolerance (inches)
• \( actual\_size \) — Measured size of the feature (inches)
• \( mmc\_size \) — Maximum Material Condition size (inches)

Explanation: The equation calculates the additional positional tolerance available when a feature departs from its MMC size.

3. Importance of MMC Calculation

Details: Calculating True Position with MMC is crucial for proper GD&T analysis, ensuring parts meet design requirements while maximizing manufacturability.

4. Using the Calculator

Tips: Enter True Position tolerance, actual measured size, and MMC size in inches. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is Maximum Material Condition (MMC)?
A: MMC is the condition where a feature contains the maximum amount of material within its size tolerance (minimum hole size or maximum shaft size).

Q2: When should MMC be used in True Position?
A: MMC should be used when the feature control frame includes the MMC modifier (Ⓜ) after the positional tolerance value.

Q3: Can MMC be used with other GD&T symbols?
A: MMC can be applied to various geometric tolerances including position, concentricity, and symmetry when properly specified.

Q4: What's the difference between MMC and LMC?
A: MMC (Maximum Material Condition) is the condition with the most material, while LMC (Least Material Condition) is the condition with the least material.

Q5: How does MMC affect inspection?
A: MMC allows for additional tolerance as the feature departs from MMC, which can be verified using functional gages or calculated mathematically.