Microsoft power point 9781605253084-ch05 [compatibility mode]

5 MultiviewDrawings5 MultiviewDrawings

• Explain the relationship between an orthographicprojection and a multiview drawing.

• Explain three visualization principles for multiviewdrawings.

• Identify and define the three dimensions of anobject.

• Define the three regular views.

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• Explain the relationship between an orthographicprojection and a multiview drawing.

• Explain three visualization principles for multiviewdrawings.

• Identify and define the three dimensions of anobject.

• Define the three regular views.

• Identify three principal planes of projection.• Identify the three types of flat surfaces.• Explain characteristics of cylindrical surfaces.• Explain characteristics of fillets, rounds, and

runouts.• Identify differences between third-angle and first-

angle projection.

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• Identify three principal planes of projection.• Identify the three types of flat surfaces.• Explain characteristics of cylindrical surfaces.• Explain characteristics of fillets, rounds, and

runouts.• Identify differences between third-angle and first-

angle projection.

Orthographic Projection• Created by projecting the points of a three-

dimensional object onto a two-dimensional plane

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Multiview Projection• Orthographic projection consisting of

systematically arranged views to describe anobject

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Definition Summary• Orthographic projection, multiview projection, and

multiview drawing are interchangeable terms• Represents the main type of drawing views used

in industrial prints

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Selection of Views• Six normal views:

– Front– Back– Top– Bottom– Right side– Left side

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• Six normal views:– Front– Back– Top– Bottom– Right side– Left side

Selection of Views• Three “regular” views commonly used in

education:– Front– Top– Right side

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• Three “regular” views commonly used ineducation:– Front– Top– Right side

Selection of Views

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Dimensions of an Object• Height is how tall the object is, as measured on

the front view• Width is how wide the object is, as measured on

the front view• Depth is how deep the object is from front to back• Each dimension appears twice in the three regular

views• “Length” and “breadth” are terms not used

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• Height is how tall the object is, as measured onthe front view

• Width is how wide the object is, as measured onthe front view

• Depth is how deep the object is from front to back• Each dimension appears twice in the three regular

views• “Length” and “breadth” are terms not used

Dimensions of an Object

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Three Orientation Possibilities• Perpendicular• Parallel• Inclined

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Three Projection Possibilities• Edge view• True size and shape• Foreshortened shape

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Three Principal Planes of Projection• Frontal plane• Horizontal plane• Profile plane

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Three Types of Flat Surfaces• Normal

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Three Types of Flat Surfaces• Inclined

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Three Types of Flat Surfaces• Oblique

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Cylindrical and Curved Surfaces

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Meanings of a Multiview Line• A—Edge view of a flat

or curved surface• B—Intersection of two

surfaces (just an edge)• C—Maximum contour

of a curved surface

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• A—Edge view of a flator curved surface

• B—Intersection of twosurfaces (just an edge)

• C—Maximum contourof a curved surface

First-Angle and Third-AngleProjection

• Dividing space into quadrants– Historical development of projection theory used two

planes to divide space– After projections, the two planes are revolved into one,

with quadrants two and four “collapsed”

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• Dividing space into quadrants– Historical development of projection theory used two

planes to divide space– After projections, the two planes are revolved into one,

with quadrants two and four “collapsed”

First-Angle and Third-AngleProjection

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Third-Angle Projection• Used in the United States

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First-Angle Projection• Used in Europe

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• What is the relationship between orthographicprojection and a multiview drawing?

Each view in a multiview drawing is based onorthographic projection

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Each view in a multiview drawing is based onorthographic projection

• What are the three basic dimensions of anyobject?

Height, width, and depth

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Height, width, and depth

• What are the three regular views on a multiviewdrawing?

Front, top, and right side

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Front, top, and right side

• What are the three principal planes of projection?

Frontal, horizontal, and profile

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Frontal, horizontal, and profile

• Briefly describe the three visualization principlesfor multiview drawings.

Principle One: A flat surface is orientedperpendicular, parallel, or inclined to a plane ofprojection.

Principle Two: All flat surfaces appear as eithera line, true size and shape, or foreshortened.

Principle Three: All surfaces appear in everyview.

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Principle One: A flat surface is orientedperpendicular, parallel, or inclined to a plane ofprojection.

Principle Two: All flat surfaces appear as eithera line, true size and shape, or foreshortened.

Principle Three: All surfaces appear in everyview.

• What are the three types of flat surfaces?

Normal, inclined, and oblique

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Normal, inclined, and oblique

• Briefly explain the characteristics of cylindricalsurfaces in multiview drawings.

Cylindrical surfaces are made up of thousandsof elements. If a flat surface is tangent to thecylindrical surface, no line appears at theelement of tangency.

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Cylindrical surfaces are made up of thousandsof elements. If a flat surface is tangent to thecylindrical surface, no line appears at theelement of tangency.

• Explain characteristics of fillets, rounds, andrunouts.

Fillets are interior rounded edges. Rounds areexterior rounded edges. A line may be shownin projection for fillets and rounds if neededfor clarity. Runouts occur when a roundedcorner intersects a curved surface and theedge “tails” out. Runouts are usuallyrepresented in projection.

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Fillets are interior rounded edges. Rounds areexterior rounded edges. A line may be shownin projection for fillets and rounds if neededfor clarity. Runouts occur when a roundedcorner intersects a curved surface and theedge “tails” out. Runouts are usuallyrepresented in projection.

• What is the difference between third-angle andfirst-angle projection?

In third-angle projection, the object resides inthe third angle of space, resulting in the topview being located above the front view. Infirst-angle projection, the object resides in thefirst angle of space, resulting in the top viewbeing located below the front view.

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In third-angle projection, the object resides inthe third angle of space, resulting in the topview being located above the front view. Infirst-angle projection, the object resides in thefirst angle of space, resulting in the top viewbeing located below the front view.