Advanced Geometric Dimensioning & Tolerancing (GD&T)

Course Description
Like any language, a deeper understanding is built on the fundamentals. This Advanced course explores in greater depth many GD&T concepts, to promote understanding, build awareness of additional tools not covered in the Basic course, and help students understand how the geometric language is applied to real parts and its ramifications on design and documentation. Advanced concepts, deeper explanation of key topics, applications exercises and calculations are performed individually and in teams. The Advanced course reinforces fundamentals, explores pros and cons of various strategies and their effects on downstream processes, and provides applications-based exercises in which students apply what they have learned. This course addresses the consequences of various product definition strategies on part function. Application and implications of functional dimensioning and tolerancing schemes on mating parts in assemblies are emphasized throughout the course.

Anyone looking for a deeper understanding of how to apply geometric tolerancing and perform tolerance analysis will greatly benefit from this course. Even with an understanding of the fundamentals of GD&T such as datums, position with MMC and RFS modifiers, parallelism, profile etc. users typically still lack the intimate knowledge of how to expertly and confidently apply geometric tolerancing and perform tolerance stack-up analyses to clearly define and optimize their product designs.

Prerequisite for Advanced GD&T: It is essential that individuals understand the underlying principles of GD&T prior to enrolling. At least one Basic GD&T workshop/course is highly recommended as a prerequisite. 

Who Should Attend
This course is appropriate for CAD draftspersons, tool designers, technical inspectors, mechanical engineering technicians, machine shop and tool room supervisors. Design, manufacturing, and project engineers, quality control personnel, engineering managers and supervisors will also find the course beneficial.

Learning Objectives
The emphasis of the Advanced course is on helping students learn how to apply GD&T to achieve the mating and functional requirements of parts, to understand the pros and cons of various approaches, and to gain experience working with more advanced applications. Students will expand their understanding of the implications of their specifications on function, manufacturing, inspection, and quality. The Advanced course introduces the topic of tolerance stack-ups.

Course Outline

  1. Position
    • Applications for MMC, RFS & LMC material modifiers
    • Composite tolerancing – one datum feature reference, two datum feature references
    • Dual segment position tolerancing
    • Cylindrical tolerance zone, rectangular tolerance zone, spherical tolerance zone, conical tolerance zone
    • Position for irregular features of size
    • Virtual condition & resultant condition
    • Position verification at MMC, LMC
  2. Datum review
    • Datum reference frames and degrees of freedom, datum feature simulators
    • Establishing DRFs:  planar surfaces; plane, axis, plane; axis, plane, center plane
    • Datum feature precedence
    • Customized datum reference frame
  3. Datum feature modifiers
    • Datum feature modifiers – MMB, LMB, and RMB
    • Development of DRF at MMB, MMB; comparison between modifiers
    • Simultaneous requirements
    • Secondary datum feature at MMB; tertiary datum feature at MMB; calculating allowable datum feature shift
    • Applications for datum feature modifiers
  4. Advanced Datum reference frame concepts
    • Moveable datum targets
    • Rotational control
    • Translation modifier
    • Applications and establishment of the DRF
  5. Advanced profile control concepts
    • Free state variation, non-rigid parts
    • Non-uniform profile
    • Composite profile – one datum feature, two datum features, irregular features
    • Profile for coplanarity & multiple profile controls
  6. Coaxial tolerances
    • Comparison among circular runout, total runout, position, profile, concentricity, and symmetry
    • Applications of various coaxial tolerances
  7. Boundaries
    • Boundaries RFS, MMC, LMC
    • Inner & Outer boundary stack-up calculations
  8. Introduction to Tolerance Stack-Ups
    • Design practice
    • The tolerance stack-up chain
    • Preliminary tolerance assignment
    • Analysis and assignment methods
    • Geometric controls in tolerance analysis

Course Format
16 hours
Combination lecture/discussion, individual and group work sessions, and large print review
Available at QSG’s training facilities and on-site at your organization

GeoTol Pro Fundamentals Workbook; Technical Consultants Incorporated

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