Critical Concepts of Tolerance Stacks ASME Y14.5 1994, 2009, 2018 - Advanced Level

Using tolerance stacks ensures that parts fit together properly, reducing scrap and rework, thereby increasing value. This 3-day advanced-level course includes everything covered in the 2-day foundational-level course. It explains how to use tolerance stacks to analyze product designs and how to use geometric tolerances in stacks. You’ll learn the essential methods used for creating 1D part and assembly tolerance stacks, including these six critical concepts:

    1. The importance of stacks
    2. The two-column stack method using the SAE stack spreadsheet
    3. Determining a stack path
    4. Creating 1D part and assembly stacks
    5. Interpreting GD&T
    6. Resolving assumptions and inane tolerances

The course discusses how virtual condition and worst-case boundaries affect part assembly. You’ll practice calculating part and assembly stacks using directly toleranced dimensions, runout/concentricity, equal bilateral/unilateral profile, position tolerances (RFS & MMC) with datum references at RMB and MMB, using form and orientation tolerances applied to features (surfaces) and features of size (e.g., holes, pins, slots, tabs, etc.). You’ll also gain experience performing tolerance stacks that involve various types of geometric tolerances (e.g., runout, position, profile, etc.). Each lesson focuses on a key learning goal by giving you the opportunity to work on and master two to five specific performance objectives.

This advanced-level course also includes:
  • How to properly document tolerance stacks on the job
  • The different engineering methods that can be used to determine which stacks are required
  • How to evaluate a stack answer and the benefits of doing so
  • How to establish a design goal and its benefits
  • How to utilize tolerance stacks to optimize part tolerances
  • Fourteen additional practice problems

The knowledge and skills acquired will enable you to increase your understanding of part function. You’ll be able to discover and resolve problems early in the product development process rather than in prototype or production. You’ll make more intelligent design decisions, be better able to evaluate design proposals and change requests, and have an increased understanding of GD&T.

Each attendee should bring a laptop with Excel and PowerPoint to utilize the Tolerance Stacks Digital Exercise workbooks.

Each attendee receives:
  • A copy of the Critical Concepts of Tolerance Stacks Course Book (includes drawing package, exercises, and answers) PDF and/or print
  • An SAE Excel Tolerance Stacks Calculation Workbook
  • An SAE PowerPoint Tolerance Stacks Vector Loop Workbook
  • An SAE Excel Tolerance Stacks Spreadsheet to use on the job
  • A Tolerance Stacks Summary Chart PDF
  • A Y14.5 1982 / 1994 / 2009 / 2018 Effects on Tolerance Analysis Comparison Chart PDF

The course features more than 40 practice problems and in-depth coverage of tolerance stacks applications based on the ASME Y14.5 Standard.

What Will You Learn

After completing this advanced-level course, you’ll be able to:
  • Describe how virtual condition and worst-case boundaries affect the assembly of parts
  • Explain the importance of tolerance stacks and be familiar with the SAE 1D two-column limit stack methods and the SAE tolerance stack spreadsheet
  • Calculate part stacks using directly toleranced dimensions, runout and concentricity tolerances, equal bilateral and unilateral profile tolerances, multiple geometric tolerances, position tolerances at RFS and MMC with datum features referenced at RMB and MMB
  • Calculate assembly stacks using directly toleranced dimensions, runout and concentricity tolerances, equal bilateral and unilateral profile tolerances, multiple geometric tolerances, position tolerances at RFS and MMC with datum features referenced at RMB and MMB
  • Calculate stacks using form and orientation tolerances applied to features (surfaces) and features of size (e.g., holes, pins, tabs, slots, etc.)
  • Describe how to use stacks on the job, including documenting stacks, determining which stacks are required, how to evaluate a stack answer, establishing a design goal, and optimizing part tolerances

Is This Course For You

This course is valuable for product designers, engineers, and checkers responsible for the fit and function of the product. Gage designers; process and manufacturing engineers; supplier quality engineers/professionals; inspectors; and technicians will also benefit from this course.

Materials Provided

This data is not available at this time

Course Requirements

This data is not available at this time

Topics

DAY ONE
Introduction
Gearbox Overview
  • Major gearbox functions
  • Terms and concepts
Virtual Condition/Worst-Case Boundary Concepts
  • Concepts/calculations
  • Clearance/interference between mating part features
Introduction to Tolerance Stacks
  • Stack definition
  • Importance/purpose/benefits of stacks
  • When stacks should be calculated
Introduction to 1D Stack Methods
  • Definition and stack conventions
  • Effects of rounding
  • Importance of design goals
  • Five-step part stack process
SAE Stack Spreadsheet
  • Major parts of the stack spreadsheet
  • Stack summary chart and abbreviations
  • Benefits and features of the spreadsheet
Part Stacks Using Directly Toleranced Dimensions
  • Applying the five-step stack method
  • Stack path vector loop for part stacks
  • Calculating part stacks
  • Shortcomings of using directly toleranced dimensions and their impact on stacks
Part Stacks Using Runout and Concentricity Tolerances
  • Stack vector loop between coaxial diameters
  • Entering runout tolerances in the stack spreadsheet
  • Part stacks using runout tolerances
  • Similarities between calculating concentricity and runout tolerances in a tolerance stack
Part Stacks Using Profile Tolerances
  • Stack vector loop using profile tolerances
  • Assembly stacks using equal bilateral and unilateral profile tolerances
Part Stacks Using Position Tolerances at RFS
  • Stack vector loop using position tolerances
  • Entering position tolerances at RFS and basic dimensions in the stack spreadsheet
  • Part stacks using position tolerances at RFS and datum features referenced at RMB
Part Stacks Using Position Tolerances at MMC
  • Stack vector loop using position tolerances
  • Entering position tolerances at MMC and basic dimensions in the stack spreadsheet
  • Bonus tolerances
  • Part stacks using position tolerances at MMC and datum features referenced at RMB
Part Stacks Using Position Tolerances with Datum Features Referenced at MMB – Basics of Datum Feature Shift
  • Recognizing the impact of datum feature shift on stacks
  • Stack path on a part with position tolerances at MMC and datum features referenced at MMB
  • Entering datum feature shift tolerances in the correct columns on the stack spreadsheet
DAY TWO
Part Stacks Using Position Tolerances with Datum Features Referenced at MMB – Datum Feature Shift Exceptions
  • Recognizing the four cases where datum feature shift does not apply in a stack
  • Calculating stacks on a part with position tolerances where datum feature shift is not applicable
Part Stacks Using Multiple Geometric Tolerances
  • Stack vector loop using multiple geometric tolerances
  • Part stacks using various types of geometric tolerances (e.g., position, runout, and profile tolerances)
Assembly Stacks Using Directly Toleranced Dimensions
  • Six-step assembly stack process
  • Stack vector loop for assembly stacks
  • Calculating assembly stacks
Assembly Stacks Using Runout Tolerances
  • Stack vector loop between coaxial diameters
  • Assembly stacks using circular and total runout tolerances
Assembly Stacks Using Profile Tolerances
  • Stack vector loop using profile tolerances
  • Assembly stacks using equal bilateral and unilateral profile tolerances
Assembly Stacks Using Position Tolerances at MMC and Datum Features Referenced at MMB
  • Stack vector loop using position tolerances
  • Assembly stacks using position tolerances at MMC and datum features referenced at MMB
Assembly Stacks Using Form and Orientation Tolerances Applied to Features (Surfaces)
  • Stack vector loop using form tolerances
  • 'To and Thru' rule
  • 'Adjacent or Offset' rule
  • Assembly stacks using straightness and flatness tolerances applied to surfaces
  • Assembly stacks using perpendicularity and parallelism applied to surfaces
Assembly Stacks Using Form and Orientation Tolerances Applied to Features of Size
  • Stack vector loop using form and orientation tolerances applied to features of size
  • Assembly stacks using flatness and straightness tolerances applied to features of size
  • Assembly stacks using perpendicularity applied to features of size
Assembly Stacks Using Multiple Geometric Tolerances
  • Stack vector loop using multiple geometric tolerances
  • Assembly stacks using various types of geometric tolerances (e.g., position, runout, and profile tolerances)
Using Stacks on the Job*
  • The various tolerance stack documents, their purpose, and benefits
  • Different engineering methods for determining which stacks are required
  • How to evaluate a stack answer and stack vector loop by identifying special conditions that affect the stack
  • The benefits of evaluating a stack answer
  • How to establish a design goal and its benefits
  • How to use tolerance stacks to optimize part tolerances
Course Summary
  • The six critical concepts of tolerance stacks
  • Course assessment
This course contains more than 40 tolerance stacks practice exercises.

*Not covered in 2-day foundational-level course