Unit 2 Visualizing Shapes Objectives List the six

Unit 2 Visualizing Shapes

Objectives • List the six principal views of an object. • Understand the basic principles of orthographic projection. • Identify first- and third-angle projection drawings. • Visualize three-dimensional objects from orthographic drawings. • Apply proper dimensioning for project views. • Draw a missing view of an object from two given views. Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Multiview Drawing • Uses three primary views – Top view – Front view – Right side view Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

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

Orthographic Projection • Shows an object’s shape by projecting two or more views at right angles to each other Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

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

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

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

Surface Representation • True size and shape – Lines and surfaces identical to lines and surfaces of the object • Foreshortened – Lines and surfaces reduced by elimination of depth Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Visualizing Objects • • First, locate top, front, and right side views Pay attention to forms created by projections Understand the print completely Careful reading helps avoid costly mistakes Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Visualizing Objects (cont. ) • Watch for objects with identical top and right side views but different front views Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.

Drawing Missing Views • Find two of the three primary views – Top – Front – Right side • Each view has two required dimensions • Project the missing view from known dimensions Copyright Goodheart-Willcox Co. , Inc. May not be posted to a publicly accessible website.