Intended Audience:This StAIR is intended for advanced second year students (10-12 grade) with a mechanical focus.

Objective:Given the Applying GD&T StAIR a student shall be able to apply Geometric Dimensioning & Tolerancing schema to existing models and prints. Based on ASME Y14.5M-1994 standard and aligned with CIP 15.1301 curriculum requirements.

Introduction

Purpose:Today you will be reviewing both the Linear tolerancing scheme you have been exposed to as well as being introduced to a new form of tolerancing and begin applying it on our prints. That form of tolerancing is called Geometric Dimensioning & Tolerancing or simply GD&T

Applying GD&T

Tolerance defined:•The permissible range of variation in a dimension of an object.

•All manufacturing processes must allow for some variances in part geometry as it is impossible

Two forms of Tolerancing: Please select one

Why we must Apply Tolerancing To a Print

LINEAR GD&T

•Based on X&Y coordinates creating a rectangular tolerance zone for part position.•Example of tolerance zone

•TYPES OF LINEAR TOLERANCES:

Linear Tolerancing

BILATERAL

UNILATERAL

PLUS AND MINUS

LIMIT

•Tolerance dimension that allow variation in both direction from a basic dimension (+ and -). Does not need to be symmetrical•EXAMPLE:

BILATERAL TOLERANCE

•Tolerance dimension that allow variation in only one direction from a basic dimension (+ or -). •EXAMPLES:

UNILATERAL TOLERANCE

•Tolerance dimension that used to indicate the tolerance range above and below the basic dimension. Must remain symmetrical•EXAMPLE:

PLUS/MINUS TOLERANCE

•A statement of the variations that can be permitted from a given dimension. Stating both the upper and lower limit of the dimension•EXAMPLE:

LIMIT TOLERANCE

LINEAR TOLERANCE ZONE

•Based on an international standard for communicating instructions about the design and manufacturing of parts. GD&T uses universal symbols and emphasizes the function of the part. Culminating in increasing a manufactures ability to create parts based on form and providing them with a larger tolerance envelope.

•Tolerance zones GD&T VS Linear GD&T(ASME) Y14.5M-1994

GD&T

TOLERANCE ZONESGD&T VS LINEAR

GD&T ASME Y14.5M-1994

PURPOSE:The Y14.5M standard establishes uniform practices for stating and interpreting dimensioning, tolerancing, and related requirements for use on engineering drawings and in related documents.

TO FURTHER INFORMATION

TO QUIZ

APPLYINGGD&T ASME Y14.5M-1994

GD&T Can be broken down into three major categories

TYPES OF TOLERANCE

DATUM'S &FEATURE CONTROL FRAMES MODIFIERS

TYPES OF TOLERANCEFORM

PROFILE

ORIENTATION

LOCATION

RUNOUT

Geometric tolerances that limit the amount of error in the shape of a feature. Form tolerances are independent tolerances.

Powerful geometric tolerances that control the size, location, orientation, and form of a feature. Profile tolerances can be either independent or related.

Geometric tolerances that limit the direction, or orientation, of a feature in relation to other features. Orientation tolerances are related tolerances.

Geometric tolerances that limit the location or placement of features. Location tolerances are related tolerances.

Geometric tolerances that simultaneously limit the form, location, and orientation of cylindrical parts. Runout tolerances are related tolerances requiring a datum axis.

FORM TOLERANCESTRAIGHTNESS

FLATNESS

CIRCULARITY

CYLINDICITY

A two-dimensional geometric tolerance that controls how much a feature can deviate from a straight line.

A three-dimensional geometric tolerance that controls how much a feature can deviate from a flat plane.

A two-dimensional geometric tolerance that controls how much a feature can deviate from a perfect circle.

A three-dimensional geometric tolerance that controls how much a feature can deviate from a perfect cylinder.

PROFILE TOLERANCE

PROFILE OF A LINE

PROFILE OF A SURFACE

A two-dimensional geometric tolerance that controls how much the outline of a feature can deviate from the true profile.

A three-dimensional geometric tolerance that controls how much a surface can deviate from the true profile.

ORIENTATION TOLERANCEANGULARITY

Perpendicularity

Parallelism

A three-dimensional geometric tolerance that controls how much a surface, axis, or plane can deviate from the angle described in the design specifications.

A three-dimensional geometric tolerance that controls how much a surface, axis, or plane can deviate from a 90 degree angle.

A three-dimensional geometric tolerance that controls how much a surface, axis, or plane can deviate from an orientation parallel to the specified datum.

LOCATION TOLERANCEPositional tolerance

Symmetry

Concentricity

A three-dimensional geometric tolerance that controls how much the location of a feature can deviate from its true position.

A three-dimensional geometric tolerance that controls how much the median points between two features may deviate from a specified axis or center plane.

A three-dimensional geometric tolerance that controls how much the median points of multiple diameters may deviate from the specified datum axis.

RUNOUT TOLERANCE

CIRCULAR RUNOUT

TOTAL RUNOUT

A two-dimensional geometric tolerance that controls the form, orientation, and location of multiple cross sections of a cylindrical part as it rotates.

A three-dimensional geometric tolerance that controls the form, orientation, and location of the entire length of a cylindrical part as it rotates.

DATUM'S AND FEATURE CONTROL FRAMES

FEATUREA physical feature of a part that naturally contains variation and imperfections. A corner, edge, flat surface, or hole are all examples of possible features.

FEATURE CONTROL FRAME

A series of compartments containing symbols and values that describe the tolerance of a feature. The order and purpose of these compartments follow a consistent standard.

DATUM'SAn imaginary, perfect geometric shape or form. A perfect point, line, flat plane, circle, or cylinder are all examples of possible datums.

DATUM FEATUREA physical feature that acts as an acceptable substitute for a datum. Datum features relate the various features of the part to each other.

DATUM REFERENCE FRAME

Three imaginary planes perpendicular to one another that are mapped onto the part to relate features to each other.

FEATURE CONTROL FRAME

DATUM'S

DATUM FEATURE

DATUM REFERENCE FRAME

STRAIGHTNESS TOLERANCEStraightness tolerance applied to axis: What is means:

FLATNESS TOLERANCEFLATNESS CALLED OUT

WHAT IS ACTUALLY MEANS

CIRCULARITY TOLERANCETolerance applied to cylinder

Implied Meaning:

CYLINDRICITY TOLERANCETolerance applied

Implied Meaning

PROFILE OF A LINEApplied to a print

What it implies

PROFILE OF A SURFACE

Applied to a print

What it implies

ANGULARITY TOLERANCE

PERPENDICULARITY TOLERANCE

PARALLELISM TOLERANCE

POSITION

SYMMETRY

CONCENTRICITY

RUNOUT TOLERANCE

TOTAL RUNOUT TOLERANCE

MODIFIERSALL AROUND

SYMBOLA circle placed on the bend of the leader line of a profile control.

BASIC DIMENSION

A numerical value used to describe the theoretically exact size, true profile, orientation, or location of a feature or datum target.

BETWEEN SYMBOL

A double ended arrow that indicates the tolerance zone extends to include multiple surfaces.

CONTROL RADIUS

A radius with no flats or reversals allowed. The symbol for a controlled radius is "CR."

LEAST MATERIAL CONDITION

The condition in which a feature of size contains the least amount of material everywhere within the stated limits of size.

MAXIMUM MATERIAL CONDITION

The condition in which a feature of size contains the maximum amount of material everywhere within the stated limits of size.

PROJECTED TOLERANCE ZONE

A tolerance zone that is projected above the part surface.

RADIUSA straight line extending from the center of an arc or circle to its surface.

BASIC DIMENSION

BETWEEN SYMBOL

LEAST MATERIAL CONDITION

MAXIMUM MATERIAL CONDITION

PROJECTED TOLERANCE ZONE

CONCENTRICITY IS A FORM TOLERANCE

QUESTION 1

Concentricity

FALSETRUE

LOCATION TOLERANCE

QUESTION 1 ANSWER

ConcentricityA three-dimensional geometric tolerance that controls how much the median points of multiple diameters may deviate from the specified datum axis.

NEXT QUESTION

OOPS

QUESTION 2

TOTAL RUNOUTA two-dimensional geometric tolerance that controls the form, orientation, and location of multiple cross sections of a cylindrical part as it rotates.

FALSETRUE

GOOD WORK

QUESTION 2 ANSWER

NEXT QUESTION

TOTAL RUNOUTA three-dimensional geometric tolerance that controls the form, orientation, and location of the entire length of a cylindrical part as it rotates.

QUESTION 3

NOYES

ParallelismA three-dimensional geometric tolerance that controls how much a surface, axis, or plane can deviate from a 90 degree angle.

IS THIS THE CORRECT DEFINITION

GOOD WORK

QUESTION 3 ANSWER

NEXT QUESTION

ParallelismA three-dimensional geometric tolerance that controls how much a surface, axis, or plane can deviate from an orientation parallel to the specified datum.

QUESTION 4

FALSETRUE

GD&T PROVIDES A DESIGNER AN IMPROVEMENT IN THE USEABLE

TOLERANCE ZONE OF 52%

57% INCREASE

QUESTION 4 ANSWER

NEXT QUESTION

QUESTION 5

NOYES

PROFILE OF A SURFACE

A two-dimensional geometric tolerance that controls how much the outline of a feature can deviate from the true profile.

IS THIS CORRECTLY DEFINED

GOOD

QUESTION 5 ANSWER

NEXT QUESTION

PROFILE OF A SURFACE

A three-dimensional geometric tolerance that controls how much a surface can deviate from the true profile.

QUESTION 6

FALSETRUE

THIS IS AN EXAMPLE OF A DATUM REFERENCE FRAME

ALMOST DONE

QUESTION 6 ANSWER

NEXT QUESTION

FEATURE CONTROL FRAME

A series of compartments containing symbols and values that describe the tolerance of a feature. The order and purpose of these compartments follow a consistent standard.

QUESTION 7

FALSETRUE

CIRCULARITY

IS THIS THE CORRECT SYMBOL FOR CIRCULARITY

GETTING CLOSE

QUESTION 7 ANSWER

NEXT QUESTION

CIRCULARITYA two-dimensional geometric tolerance that controls how much a feature can deviate from a perfect circle.

QUESTION 8

NOYES

DATUM'SAn imaginary, perfect geometric shape or form. A perfect point, line, flat plane, circle, or cylinder are all examples of possible datums.

IS THIS CORRECTLY DEFINED

NICE

QUESTION 8 ANSWER

NEXT QUESTION

QUESTION 9

NOYES

STRAIGHTNESSA two-dimensional geometric tolerance that controls how much a feature can deviate from a straight line.

IS THIS THE CORRECT SYMBOL FOR STRAIGHTNESS

NICE WORK

QUESTION 9 ANSWER

NEXT QUESTION

STRAIGHTNESSA two-dimensional geometric tolerance that controls how much a feature can deviate from a straight line.

QUESTION 10

FALSETRUE

FORM TOLERANCES ARE INDEPENDENT FROM OTHER

FEATURES.

CONGRATULATIONSPLEASE SEE THE INSTRUCTOR FOR

YOU FIRST ASSIGNMENT

QUESTION 10 ANSWER

FINISH