Unit 5 Multiview Drawings Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly...

Unit 5Multiview Drawings

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website.

Learning Objectives

• Define spatial visualization.• Explain the relationship between an orthographic

projection and a multiview drawing.• Identify and define the three dimensions of an

object.• Define the six principal views and the three

regular views.• Identify the three principal projection planes.


Learning Objectives

• Explain three visualization principles for multiview drawings.

• 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.• Discuss computer-generated views.


The Role of Spatial Skills

• Spatial visualization can be defined as the mental visualization of 2D and 3D shapes and objects, including such tasks as imagining objects in the mind as they are rotated, moved, or reflected in a mirror


Spatial Visualization Tools

• Visualization of rotations



• Mental rotation with two correct rotations



• Surface development test



• Mental visualization of folding and unfolding


Orthographic Projection

• Created by projecting the points of a three-dimensional object onto a two-dimensional plane


Multiview Projection

• Orthographic projection consisting of systematically arranged views to describe an object


Definition Summary

• Orthographic projection, multiview projection, and multiview drawing are interchangeable terms

• Represents the main type of drawing views used in industrial prints


Selection of Views

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


Selection of Views

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


Selection of Views


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


Dimensions of an Object


Three Orientation Possibilities• Perpendicular• Parallel• Inclined


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


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


Three Types of Flat Surfaces

• Normal



• Inclined



• Oblique


Cylindrical and Curved Surfaces


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


First-Angle and Third-Angle Projection• 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-Angle Projection


Third-Angle Projection

• Used in the United States


First-Angle Projection

• Used in Europe


Computer-Generated Views

• The benefits of creating views directly from the 3D model include: – Ease of construction– Ease of change– Accuracy in representing geometry– Intelligent association between the model and the

annotations


Computer-Generated Views

• Views created by the CAD program may need:– Individual line adjustment

for weight or dash spacing– The representation of

fillets, rounds, and runouts adjusted (see A versus B to the right)

– Conventional practices reviewed


What do you see?

Print supplied by Sunnen Products Company.

Unit 5 Multiview Drawings Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly...

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