1. Chapter 14
Auxiliary Views

2. 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

3. 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

4. Auxiliary Views for Solid Objects
FIGURE 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).

5. Auxiliary Views for Solid Objects (cont’d.)
FIGURE 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.

6. Auxiliary Views for Solid Objects (cont’d.)
FIGURE 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.

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

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

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

10. Auxiliary Views of Irregular or Curved Surfaces
FIGURE An object with two holes through an inclined surface.
FIGURE An auxiliary view of an inclined surface with holes in it.

11. 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

12. Strategies for Auxiliary Views (cont’d.)
FIGURE A truncated pyramid for constructing an auxiliary view.
FIGURE Top and front views of the truncated pyramid.

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

14. Strategies for Auxiliary Views (cont’d.)
FIGURE Point “a” transferred into the auxiliary view.
FIGURE The auxiliary view showing surface A in true shape.

15. 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

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

17. Sketching Techniques for Auxiliary Views
Parallel and perpendicular lines need to be created accurately
FIGURE Sliding triangles used to construct parallel and perpendicular lines.

18. 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