15 Direct vs. Indirect Relationships

Readers will learn:

1. How tolerances accumulate when functional relationships are held indirectly.

2. How to tolerance a three part assembly with both floating and fixed fastener conditions using:

• Direct functional tolerancing, multi-level controls, multiple datum reference frames for larger tolerances and the greatest acceptance of parts.

• Indirect tolerancing to create one set of datums for each part to allow one set-up and one gage for each part.

3. How to calculate the effects of tolerance accumulation with multiple datum reference frames.

4. The unique effects of utilizing LMC and LMB concepts on design calculations and measurement procedures.

5. To calculate minimum wall thicknesses that include datum feature shift.