5. Orientation.ppt

7/29/2019 5. Orientation.ppt

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Perpendicularity Control


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Define Perpendicularity

Perpendicularity is the condition that results

when a surface, axis, or centerplane is exactly

90 deg to a datum.

A perpendicularity control is a geometric

tolerance that limits the amount a surface, axis,

or centerplane is permitted to vary from being

perpendicular to the datum.


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Perpendicularity Applications1. Perpendicularity applied to a surface.

2. Perpendicularity applied to a planar FOS.

3. Perpendicularity applied to a cylindrical FOS.

Perpendicularity Tolerance Zones

1. Two Parallel Planes

2. A cylinder


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Perpendicularity applied to a

surface


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Interpretations

Tolerance zonetwo parallel planes that are

perpendicular to the datum plane.

Distance between tolerance plane specified

tolerance value. Important criteria all elements of the surface

must be within the tolerance zone.

Perpendicularity tolerance zone limits theflatness of toleranced feature.


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Inspection of perpendicularity


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Perpendicularity control that

contains MMC modifier


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Interpretations

Tolerance zonetwo parallel planes that are

perpendicular to the datum plane.


tolerance value. The center plane of theActual Mating Envelope


A bonus tolerance is permissible. A fixed gauge may be used to verify the

perpendicularity control.


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Perpendicularity control with

MMC modifier applied to

cylindrical FOS


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Interpretations

Tolerance zonea cylinderthat is perpendicularto the datum plane.

Diameter of the tolerance zone specified

tolerance value. The axis of the diametermust be within the

tolerance zone.

A bonus tolerance is permissible.

A fixed gauge may be used to verify theperpendicularity control.


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Angularity Control

Angularity is the condition of a surface, center

plane, or axis being exactly at the specified

angle.

An angularity control is a geometric tolerance

that limits the amount a surface, center plane, or

axis is permitted to vary from its specified angle.


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Angularity applications

1. Angularity applied to a surface.

2. Angularity applied to a cylindrical FOS.

Angularity tolerance zones

1. Two parallel planes

2. A cylinder


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Angularity applied to a surface.


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Interpretations

Tolerance zonetwo parallel planes that areperpendicular to the datum plane.


tolerance value. Important criteria all elements of the surface


Tolerance zone is oriented relative to the datum

plane by a basic angle. Angularity tolerance zone limits the flatness of

toleranced feature


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Angularity control applied to a

diametrical FOS


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Interpretations

Tolerance zonea cylinder.

Diameterof the tolerance zone specifiedtolerance value.

The axis of the toleranced feature must be withinthe tolerance zone.

Tolerance zone is oriented relative to the datumplane by a basic angle.

An implied 90 deg basic angle exists in otherdirection


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Inspection of Angularity


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Paral lel ism Con trol

Parallelism is the condition of a surface, center

plane, or axis being exactly parallel to the

datum.

An parallelism control is a geometric tolerance

that limits the amount a surface, center plane, or

axis is permitted to vary from being parallel to

the datum.


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Parallelism Applications

Parallelism applied to a surface.

Parallelism applied to a cylindrical FOS.

Parallelism Tolerance Zones

1. Two parallel planes.

2. A cylinder.


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Parallelism Applied To a Surface


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Interpretations

Tolerance zonetwo parallel planes that areparallel to the datum plane.

Tolerance zone is located within the limits of sizedimension.

Distance between tolerance plane specifiedtolerance value.

Important criteria all elements of the surface

must be within the tolerance zone. Parallelism tolerance zone limits the flatness of

toleranced feature.


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Parallelism Applied to a FOS at

MMC


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Interpretation

Tolerance zonea cylinderthat is parallel to thedatum plane.

Diameter of the tolerance zone specifiedtolerance value.

The axis of the diametermust be within thetolerance zone.

A bonus tolerance is permissible.

A fixed gauge may be used to verify the

parallelism control. Parallelism tolerance zone limits flatness of the

toleranced feature.


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Inspection


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LOCATION

TOLERANCES

Concentricity control


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Concentricity control

This is a type oflocation control.

A median point is the midpoint of a two-point measurement.

A concentricityis the condition where the

median points of all diametrically opposedelements of a cylinder (or a surface ofrevolution) are congruent with the axis ofdatum feature.

A concentricity controlis geometrictolerance that limits the concentricity errorof a part feature.


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Example:

T l f t i it t l


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Tolerance zone for a concentricity controlis three dimensional.

Tolerance zone of concentricity control is acylinder.

The cylinder is coaxial with the datum axis

and diameter of the cylinder equal to theconcentricity control tolerance value.

Median points must lie within thecylindrical tolerance zone.

When using concentricity control, thespecified tolerance and datum referencealways apply on an RFS basis.

Example


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Example


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Concentricity application

Concentricity is used when:

Precise balance of part.

Equal wall thickness.

Equal distribution of mass.


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Inspecting concentricity


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Inspecting Concentricity


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SYMMETRY DEFINITION

Symmetry is the condition where the median

points of all opposed elements of two or more

feature surfaces are congruent with the axis or

centerplane of a datum feature.

A symmetry controlis a geometric tolerance

that limits the symmetry error of a part feature.


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SYMMETRY

ZONE OF TOLERANCE :- TWO PARALLEL PLANES

SYMBOL :-


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A symmetry control may only be applied to part

features that are shown symmetrical to the

datum centerplane.


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The tolerance zone is centered about the datum

centerplane. The width between the planes is

equal to the symmetry control tolerance value.


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When using a symmetry control, the specified

tolerance and the datum references must

always be applied on an RFS basis.

TECHNOTE

The tolerance zone is two parallel planes

centered about a datum axis or centerplane.

The median points of the toleranced feature



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Inspecting Symmetry

When inspecting this part, three separate checks

are required :

size of the

slot,

its Rule #1

boundary and

its symmetry.

5. Orientation.ppt

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