This article takes you through a simple example of how tolerance stack up analysis is carried out to find unknown dimensions and gaps

Consider a component as shown with dimensions and tolerances given .

How can we find the specification in red?

**Generic process for Worst case tolerance stack up analysis**

- Label the distance to be studied A-B
- Positive and negative directions are set
- Left to Right is positive
- Right to left is negative
- Develop loop diagram starting from A to B
- Start from A and move towards B through Loop
- The dimensions in positive direction are added together and dimensions in negative are added together
- Negative dimensions sum is subtracted from positive direction sum .
- All tolerances are added with each other . The total added tolerance is possible allowed variation for distance being studied

Loop Diagram with the tolerance analysis table:

For a full course on Tolerance stackup analysis with and without GD&T

have a look here : Basics of Tolerance analyses : Stackups and Fits

Categories: : GD & Tolerancing