WORKING DRAWINGS Footer Text 10192021 1 Theory of

WORKING DRAWINGS Footer Text 10/19/2021 1

Theory of Shape Description • When describing three dimensional objects we normally consider the part as having; o length, width and height or o width, depth and height or o length, width and thickness • General Rule: o Distances from left to right are referred to as width or length. o Distances from front to back as depth or width, and vertical distances as heights. 10/19/2021 2

Orthographic Projection • What are Orthographic Views? o the view you would see looking directly at one side or "face" of the object. o describes the features of the object completely and accurately o helps to visualize the part 10/19/2021 3

Orthographic Projection • Types of Orthographic Views: o One view drawings: objects requiring one view only to describe it (ie. templates/paper/balls/cylindrical objects) o Two view drawings: objects that require two views to completely describe it (Ie. discs/gears/wheels) o Multi-view drawings: objects that require at least three views to completely describe it. Each view represents a different side or face of the object. The view is projected one from the other and arranged systematically 10/19/2021 4

General Rules for Selection of Views • draw views necessary to fully explain shape • the front view shows the width or length of the object and gives the most information about its shape. • when the longest dimension is drawn in the horizontal position, the object will seem more balanced. • choose views which will show most of the features as "visible" thus avoiding use of hidden lines. 10/19/2021 5

Orthographic Views 10/19/2021 6

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Fully Defining Objects • determining views o divide part into features o check that features are represented on all views o balance a drawing 10/19/2021 12