The purpose of this session is to give participants more practice in performing tolerance stacks that involve GD&T (geometric dimensioning and tolerancing), as well as an understanding of how statistical methods can impact a stack. A basic knowledge of geometric tolerancing is required, and familiarity with the basic stack spreadsheet method is recommended. The session begins by reviewing the unique factors known as "bonus tolerance" and "shift tolerance" (the "M" symbols), which are often erroneously ignored in tolerance stack-up analysis. Multiple examples will be provided to show specific applications, and practice exercises for the participants are included. Then the focus turns to the world of statistical stacks, which can often give more realistic results than a purely worst-case calculation. Participants will learn how to implement the root-sum-square (RSS) formula, as well as a modified RSS approach, along with a discussion of the caveats to consider when using these methods.

At the end of this session, participants will be able to:
  • Calculate any "bonus" and "shift" tolerances
  • Enter bonus/shift into the stack spreadsheet
  • Explain when a statistical approach is appropriate
  • Use the root-sum-square formula to calculate a stack
  • Describe modified RSS methods and why they are sometimes used
  • List the advantages of using a Monte Carlo simulation approach

Session Outline:
  • Brief review of MMC and LMC
  • Determing the bonus and shift tolerances
  • Entering bonus and shift into the spreadsheet
  • Review of simple statistical concepts
  • The root-sum-square (RSS) formula
  • Modified RSS formulas (Bender and Gilson factors)
  • Monte Carlo simulation method

Who Should Attend:
  • Manufacturing engineers
  • Product engineers
  • Designers
  • Quality personnel

Training Session Information
Date Presented:
April 25, 2013 2:00 PM Eastern
1 hour, 30 minutes
Tolerance Stacks: Advanced Tolerance Stacks
Speaker Information
John-Paul Belanger   [ view bio ]
Individual topic purchase: Selected
Recertification Credit : 1.00
This session is available as recertification credit for individuals who have earned a SME certification.
Preview Tolerance Stacks: Advanced Tolerance StacksPreview Tolerance Stacks: Advanced Tolerance Stacks
SME Member Price: $89.00
Non-Member Price:$109.00