Chapter 14

Chapter 14

Auxiliary Views

Objectives• Describe an auxiliary view• Describe situations where an auxiliary

view is desired• Locate top-adjacent, front-adjacent, and

side-adjacent auxiliary views constructed from primary views

• Create an auxiliary view of an inclined surface

Introduction• Auxiliary views are used to determine:

– True shape of inclined or oblique surfaces– Visibility of lines and planes– Shortest distance between two lines– Shortest distance from point to plane– Slope of line or plane– Angle between two planes– Intersection of two planes

Auxiliary Views for Solid Objects

FIGURE 14.01. The image of the object is projected onto a horizontal surface to create the top view in (a). The front and top views are shown in (b).

Auxiliary Views for Solid Objects (cont’d.)

FIGURE 14.02. An object with an inclined surface shown in the preferred orthogonal view configuration with top, front, and right-side views. Surface A is parallel to the top viewing plane (and, therefore, will be shown in its true shape in the top view) and in its edge view in the front and right-side views.

Auxiliary Views for Solid Objects (cont’d.)

FIGURE 14.03. Surface B isseen in an edge view in the front view but is not seen in its true shape in either the top orright-side views.

Auxiliary Views for Solid Objects (cont’d.)

FIGURE 14.04. An additionalplane (pane) added to the glassbox to show the true shape ofthe inclined surface.

FIGURE 14.05. The glass boxunfolded, showing the top,front, right-side, and auxiliaryviewing planes on a single plane.

FIGURE 14.08. The glass boxopened to show proper viewalignment.

Auxiliary Views for Solid Objects (cont’d.)

FIGURE 14.09. Comparisonbetween adjacent andrelated views.

Auxiliary Views for Solid Objects (cont’d.)

Auxiliary Views of Irregular or Curved Surfaces

FIGURE 14.11. An object with two holes through an inclined surface.

FIGURE 14.12. An auxiliary view of an inclined surface with holes in it.

Strategies for Auxiliary Views• Creating auxiliary view that shows inclined

surface in true size and shape:– 1. Identify edge view in one primary view– 2. Sketch “fold” line parallel to edge view– 3. Label all of the fold lines– 4. Project the points that define the surface

along rays perpendicular to fold line– 5. Get projected dimensions into auxiliary view

by observing same dimension in related view

Strategies for Auxiliary Views (cont’d.)

FIGURE 14.13. A truncated pyramid for constructing an auxiliary view. FIGURE 14.14. Top and front

views of the truncated pyramid.

FIGURE 14.15. The fold line for theauxiliary view, with labels added.

FIGURE 14.16. Projection raysadded, extending from the edgeview into the auxiliary view.

Strategies for Auxiliary Views (cont’d.)

FIGURE 14.17. Point “a” transferred into the auxiliary view.

Strategies for Auxiliary Views (cont’d.)

FIGURE 14.18. The auxiliary view showing surface A in true shape.

Solid Modeling Considerations in Creating Auxiliary Views

• Creating auxiliary views by hand is sometimes tedious and often error-prone

• 3-D model contains all information; auxiliary views might not be necessary

• Creating auxiliary views from 3-D model is easy

Solid Modeling Considerations in Creating Auxiliary Views (cont’d.)

FIGURE 14.30. An object with an oblique surface created by a solid model can easily be presented in any view orientation, including a normal (i.e., true shape) view of the oblique surface.

Sketching Techniques for Auxiliary Views

• Parallel and perpendicular lines need to be created accurately

FIGURE 14.31. Sliding triangles used to construct parallel and perpendicular lines.

Summary• Discussed uses of auxiliary views with

respect to inclined surfaces• Created auxiliary views based on

principles from orthographic projection• Discussed the impact of 3-D modeling on

auxiliary views