Creating Orthographic Projection Sketches TEC - 116

Review of Principle Views A 3D object can be viewed from six perpendicular directions –Front and Rear –Top and Bottom –Right and Left

Review of Principle Dimensions Width, Height, and Depth Front View –Height and Width only Right Side View –Depth and Height only Top View –Depth and Width only

Views are arranged on the paper in a standard way

Views of Normal Surfaces –Appears true size and shape on the plane to which it is parallel, and as a vertical or a horizontal line on adjacent planes.

Views of Inclined Surfaces –Perpendicular to one plane of projection, but inclined to adjacent planes; appears foreshortened

Views of Oblique Surfaces –Inclined to all principal planes of projection; foreshortened in all views

Which Views? A sketch or drawing should only contain the necessary views that describe the object. Choose the views that provide the most detail.

Guidelines for View Selection Orient the object so that the front view shows the shape of the object most clearly Choose front view so that it has a large number of normal surfaces. Show the object in a usual or operating position Show the right side view & top views unless other views are better (fewer hidden lines)

Necessary Views

Single View Drawings Only show the necessary views of the object. Parts like these may be shown in a single view. One view drawing of a shim One view drawing of a connecting rod

Line Types Line patterns communicate what the line represents in the drawing Line patterns tell you information such as whether the line is hidden, visible, or a centerline, etc. Visible line Hidden line Hatching Centerline Dimension Extension Leader Cutting Plane Viewing Plane Short break Long break Phantom Stitch Chain

Sample Use of Line Types

Lines and Precedence The line types that are most frequently used in TEC 116 are visible, hidden, and center. Visible, hidden, and centerlines often coincide on the same drawing. –Visible lines take precedence –Hidden lines take precedence over center lines

General Procedures for Creating Orthographic Sketches 1.Study the object and select the desired views. 2.Lightly box-in the views keeping in mind the rules of projection and view locations. 3.Lightly sketch a miter line (45 ° angle). 4.Create the views starting with the largest, most obvious features. 5.Use projection between views to help… creating views together is often preferred. 6.Add smaller details as the sketch progresses

Instructor-Led Sketching Activity 1

Instructor-Led Sketching Activity 2