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 is seen in an edge view in the front view but is not seen in its true shape in either the top or right-side views.

Auxiliary Views for Solid Objects (cont’d.) FIGURE 14.04. An additional plane (pane) added to the glass box to show the true shape of the inclined surface. FIGURE 14.05. The glass box unfolded, showing the top, front, right-side, and auxiliary viewing planes on a single plane.

Auxiliary Views for Solid Objects (cont’d.) FIGURE 14.08. The glass box opened to show proper view alignment.

Auxiliary Views for Solid Objects (cont’d.) FIGURE 14.09. Comparison between adjacent and related views.

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.

Strategies for Auxiliary Views (cont’d.) FIGURE 14.16. Projection rays added, extending from the edge view into the auxiliary view. FIGURE 14.15. The fold line for the auxiliary view, with labels added.

Strategies for Auxiliary Views (cont’d.) FIGURE 14.17. Point “a” transferred into the auxiliary view. 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