Section 3 Descriptive Geometry Chapter 12 Auxiliary Views Section 3 Descriptive Geometry

Objectives List the basic types of auxiliary views and explain the purpose of each type. Describe the common applications of auxiliary views. Explain the projection procedures for creating auxiliary views. Draw primary and secondary auxiliary views using manual and CAD methods. © Goodheart-Willcox Co., Inc.

Auxiliary View Typically used for objects with inclined features. Common in sheet metal and packaging applications. True shape and size shown by auxiliary projections. © Goodheart-Willcox Co., Inc.

Projection Applications for Auxiliary Views True length of a line Point view of a line Edge view of a plane True size of a plane True angle between planes © Goodheart-Willcox Co., Inc.

Types of Auxiliary Views Primary auxiliary view Secondary auxiliary view Successive auxiliary view © Goodheart-Willcox Co., Inc.

Primary Auxiliary Views Projected from principal views. Reference plane numbered to identify type of projection. Line of sight perpendicular to reference plane. Depth measurements transferred with tools in manual drafting. Drawing and editing commands and tracking used in CAD. © Goodheart-Willcox Co., Inc.

Types of Primary Auxiliary Projections Frontal Horizontal Profile © Goodheart-Willcox Co., Inc.

Frontal Auxiliary Projection © Goodheart-Willcox Co., Inc.

Horizontal Auxiliary Projection © Goodheart-Willcox Co., Inc.

Profile Auxiliary Projection © Goodheart-Willcox Co., Inc.

Locating a Point in an Auxiliary View Projection made perpendicular to reference plane. Depth taken from top view. Two points projected similarly to locate a true length line. © Goodheart-Willcox Co., Inc.

Construct a True Length Line in an Auxiliary View © Goodheart-Willcox Co., Inc.

Construct a True Length Line in an Auxiliary View © Goodheart-Willcox Co., Inc.

Determining Slope Auxiliary projection made when line is oblique. Angle measured from reference plane. True angles between lines and other principal planes located similarly. © Goodheart-Willcox Co., Inc.

Using the Point Method to Develop an Inclined Surface Project points to an auxiliary view. Transfer depth measurements to establish true size surface. © Goodheart-Willcox Co., Inc.

Determining the True Angle between Two Planes Locate point view of true length line of intersection (Line AB) in auxiliary view. Project remaining points. Measure dihedral angle in auxiliary view. © Goodheart-Willcox Co., Inc.

Project Circular Features in Auxiliary Views Draw principal views and mark divisions. Project points to inclined surface. Project points to auxiliary view. Use irregular curve or ellipse template to complete feature. © Goodheart-Willcox Co., Inc.

Project Circular Features in Auxiliary Views Draw principal views and divide top view. Draw construction lines to front view. Offset lines to create auxiliary view. Draw ellipse by specifying major and minor axes. © Goodheart-Willcox Co., Inc.

Construct a Principal View Using an Auxiliary View Construct view where inclined surface is an edge (profile view). Construct auxiliary view. Project points back from auxiliary to create front view. © Goodheart-Willcox Co., Inc.

Secondary Auxiliary Views Projected from primary auxiliary view and one principal view. Typically used for oblique surfaces. View must be oriented as viewed in line of sight. Reference plane constructed perpendicular to line of sight. © Goodheart-Willcox Co., Inc.

Draw a Secondary Auxiliary View © Goodheart-Willcox Co., Inc.

Draw a Secondary Auxiliary View © Goodheart-Willcox Co., Inc.

Draw a Point View of a Line in a Secondary Auxiliary View © Goodheart-Willcox Co., Inc.

Draw a Point View of a Line in a Secondary Auxiliary View © Goodheart-Willcox Co., Inc.

Determine the True Angle between Two Planes © Goodheart-Willcox Co., Inc.

Determine the True Size and Shape of an Oblique Plane © Goodheart-Willcox Co., Inc.

Review Questions 1. What type of auxiliary view is projected from an orthographic view? Primary © Goodheart-Willcox Co., Inc.

Review Questions 2. An auxiliary view projected from a horizontal view is known as a(n) _____ auxiliary projection. horizontal © Goodheart-Willcox Co., Inc.

Review Questions 3. The true angle between two planes is called the _____ angle. dihedral © Goodheart-Willcox Co., Inc.

Review Questions 4. Which of the following must be determined using a secondary auxiliary view? A. The true length of a line. B. The point view of a line. C. The slope of a line. D. The true size of an oblique surface. D. The true size of an oblique surface. © Goodheart-Willcox Co., Inc.