Tolerance Stack-Up Analysis (GD&T Application)

Training to Apply Tolerance Stack-Up Analysis (GD&T Application)

Course Duration: 2 Days - 8 Hours/day

This 2 Days Course participants will be trained to apply tolerance stack-up analysis techniques to a wide variety of assemblies per GD&T requirements of ASME Y14.5M-1994 and ISO1101, from the very simple to the more complex situations commonly faced in industry today. Both plus and minus and geometrically toleranced assemblies will be examined and stack-up analysis taught and practiced on each. Many different datum structures will be discussed and analyzed. The concepts taught in this course are: loop analysis (also known as circuit diagrams), number charting, virtual condition, resultant condition, inner and outer boundaries, minimum airspace, maximum wall thickness, maximum interference, minimum and maximum overall dimensions, fixed and floating fastener assembly conditions, projected tolerance zones, the logic of stack-up analysis, statistical tolerancing , and much more.

Learning Objectives

  • Calculate minimum and maximum wall thickness, airspaces and interferences for assemblies.
  • Create loop analysis/circuit diagrams for tolerance stack-up analysis for both plus and minus toleranced dimensions and geometric tolerances.
  • Create both simple and complex number charts for stack-up analysis using a variety of geometric tolerances, basic dimensions, resultant conditions, virtual conditions and plus and minus toleranced dimensions.
  • Do tolerance stack-up analysis for floating fastener situations for clearance holes, screws and shafts.
  • Do tolerance stack-up analysis for fixed fastener situations using screws, clearance holes, slots, tabs, overall dimensions and projected tolerance zones for threaded holes.
  • Calculate minimum and maximum gaps for assemblies that use a variety of datum structures.
  • Learn a system of logic and mathematics to analyze tolerances.
  • Calculate the effects of angular stack-up using trigonometry and proportions.
  • Calculate statistical tolerances using a variety of methods and learn how to re-integrate these tolerances back into the assembly’s details.
  • Understand the requirements of GD&T, reduce the leadtime of design, reduce the engineering change, improve the design quality.
  • Learn how to apply GD&T to understand the design purpose of the customer, improve the reliability of product design and process design.
  • Emphasize the understanding principles of verifying GD&T
  • Learn the concept of MMC, LMC and RFS
  • Use GD&T to improve the dimension verification and inspection, understand the ASME Y14.5M-1994 requirements, such as geometric tolerance, symbols, terms, rules and application
  • Understand the differences between GD&T requirements of North America (ASME Y14.5M) and Chinese Standard of Dimensioning and Tolerances

Course Outline

#1 THE BASICS

  • Designating positive and negative routes
  • What dimensions are factors
  • How to push the parts to create the worst case
  • Which geometric tolerances are and are not factors
  • Calculating boundaries for GD&T, MMC, LMC and RFS Material Condition modifiers
  • Mean boundaries with equal bilateral tolerances

#2 STACK-UP ANALYSIS OF AN ELEVEN PART ASSEMBLY USING PLUS AND MINUS TOLERANCING

  • The calculations
  • The loop analysis chart
  • The numbers analysis chart
  • Finding MIN and MAX gaps

#3 VERTICAL vs. HORIZONTAL LOOP ANALYSES FOR FEATURES OF SIZE

  • Where to start and end
  • Graphing the loop
  • Minimum and maximum gap analysis

#4 ASSEMBLIES WITH PLUS AND MINUS TOLERANCES

  • Multiple dimension loops
  • Positive and negative values
  • Airspace vs. interferences

#5 FLOATING FASTENER FIVE PART ASSEMBLY ANALYSIS

  • Resultant conditions
  • Virtual conditions
  • Inner and outer boundaries
  • Mean boundaries
  • Complex loop analyses with geometric dimensioning and tolerancing

#6 FIXED FASTENER ASSEMBLIES

  • Calculating overall minimum and maximum assembly dimensions
  • Mixing slots, tabs, holes and shafts
  • Calculating minimum and maximum gaps within the assembly
  • Projected tolerance zones for total runout as a factor
  • Determining if geometric tolerances are a factor
  • Ruling out features and patterns as factors

#7 A RAIL ASSEMBLY

  • Threaded features
  • Multiple geometric controls
  • Projected tolerance zones
  • Gaps with and without perpendicularity as a factor
  • Calculating interference
  • Theoretically vs. physically worst case possibilities
  • When logic becomes an integral step
  • Factoring in assembly conditions
  • Maximum wall thickness vs. minimum airspace for assemblies

#8 SINGLE-PART ANALYSIS

  • Two-single segment positional controls
  • Switching datum reference frames and accumulating geometric tolerances
  • Datum features at MMC (pattern shift)
  • Envelopes of perfect form at MMC
  • Creating envelopes of perfect orientation at MMC
  • MIN and MAX axial separation
  • Datum planes vs. datum features
  • Separate requirements and accumulating tolerance
  • Tolerances in degrees; Trigonometric function introduction
  • Composite positional tolerancing

#9 FIVE PART ROTATING ASSEMBLY ANALYSIS

  • Threaded holes with projected tolerance zones
  • Mounted screws
  • Part to part analysis (from two parts to an infinite number of parts
  • Runout
  • Positional coaxiality
  • Simplifying a complex assembly
  • Determining assembly housing requirements
  • Radial clearance MIN and MAX calculations
  • Interference calculations

#10 TRIGONOMETRY AND PROPORTIONS IN TOLERANCE STACK-UP ANALYSIS

  • Rocking datum features
  • Constructing a valid datum
  • Consideration of differing orientations from measurement to assembly
  • An in-depth assembly analysis using trigonometric functions
  • Computer programs vs. a personal analysis
  • Vertical stacking as it effects horizontal housing requirements
  • When stacked parts are not flat or parallel
  • Formulae to calculate worst case fit conditions when trigonometry is a factor
  • Using proportions and trigonometry to calculate fit conditions beyond the GD&T formulae

#11 THE THEORY OF STATISTICAL PROBABILITY

  • Gaussian Frequency Curve
  • Standard Deviations
  • Plus or Minus 3 Sigma
  • Root Sum Square Formula
  • Steps to Calculate and Apply Statistical Tolerances
  • Statistical Tolerancing Applied to Plus and Minus Toleranced Assemblies
  • Statistical Tolerancing Applied to Geometric Toleranced Assemblies
  • When Best to Allow Statistical Tolerances and When it Should Not Be Allowed
  • The Logic of Statistical Tolerancing
  • Modifying the Root Sum Square Formula with a Safety/Correction Factor
  • Reintegrating the Statistical Tolerance into the Assembly

Who Should Attend

Design Engineer, Product Engineer, Quality and Technical Staff

Course Materials

Omnex Training Material with case studies as well as exercises.


Note: Omnex does not provide copies of standard(s) during training courses, but clients are encouraged to have their own copy.

Pre-Requisite

Combined abundant case studies as well as provided cases from the trainee, explain in details of the content of Tolerance of Stacking Analysis with GD&T application.

Upcoming Training

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For Implementation Support

Training to Apply Tolerance Stack-Up Analysis (GD&T Application) Program is available in multiple locations globally, including the USA, Canada, Mexico, India, Europe, Thailand, Singapore, Middle East and China.