Unit 5 Multiview Drawings Learning Objectives Define spatial

Unit 5 Multiview Drawings

Learning Objectives • Define spatial visualization. • Explain the relationship between an orthographic projection and a multiview drawing. • Identify and define three dimensions of an object. • Define the six principal views and the three regular views. • Identify the three principal projection planes. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

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 firstangle projection. • Discuss computer-generated views. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

The Role of Spatial Skills • Spatial visualization can be defined as the mental visualization of 2 D and 3 D shapes and objects, including such tasks as imagining objects in the mind as they are rotated, moved, or reflected in a mirror Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Spatial Visualization Tools • Visualization of rotations Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Spatial Visualization Tools • Mental rotation with two correct rotations Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Spatial Visualization Tools • Surface development test Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Spatial Visualization Tools • Mental visualization of folding and unfolding Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Orthographic Projection • Created by projecting the points of a threedimensional object onto a two-dimensional plane Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Multiview Projection • Orthographic projection consisting of systematically arranged views to describe an object Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Definition Summary • Orthographic projection, multiview projection, and multiview drawing are interchangeable terms • Represents the main type of drawing views used in industrial prints Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Selection of Views • Six principal views: – – – Front Back Top Bottom Right side Left side Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Selection of Views • Three “regular” views commonly used in education: – Front – Top – Right side Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

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

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

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

Three Orientation Possibilities • Perpendicular • Parallel • Inclined Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Three Projection Possibilities • Edge view • True size and shape • Foreshortened shape Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Three Principal Planes of Projection • Frontal plane • Horizontal plane • Profile plane Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Three Types of Flat Surfaces • Normal Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Three Types of Flat Surfaces • Inclined Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Three Types of Flat Surfaces • Oblique Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

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

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

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

First-Angle and Third-Angle Projection Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Third-Angle Projection • Used in the United States Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

First-Angle Projection • Used in Europe Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Computer-Generated Views • The benefits of creating views directly from the 3 D model include: – – Ease of construction Ease of change Accuracy in representing geometry Intelligent association between the model and the annotations Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

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

What do you see? Print supplied by Sunnen Products Company. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.