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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
•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
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.
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.
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
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 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.
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.
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
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.