EGR 277

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Lecture 9 EGR 110 Engineering Graphics
Reading Assignment Chapter I (Auxiliary Views)
in Engineering Graphics Workbook, Series 1.2 (or
Series 2) Sketching Assignment Sketching
Assignment 8

• Recall that we are currently studying various
  types of surfaces which are covered in
• the chapters indicated below
• Chapter E Normal Surfaces
• Chapter F Inclined Surfaces
• Chapter G Oblique Surfaces
• Chapter H Cylindrical Surfaces (todays topic)
• We will also cover one additional chapter today
• Chapter I - Auxiliary Views

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Lecture 9 EGR 110 Engineering Graphics
Reading Assignment Chapter I (Auxiliary Views)
in Engineering Graphics Workbook, Series
1.2 Sketching Assignment Sketching Assignment
8
Auxiliary Views Many objects have surfaces or
features that are not normal (parallel) to one of
the three principle planes of projection.
Therefore the surface or feature will never be
seen in True Shape (TS) in any principle view.
For example, an inclined plane is never seen in
TS. Auxiliary views are used to show such planes
in TS. Auxiliary View a view obtained by a
projection on any plane other than a principle
plane. Primary Auxiliary View a view from a
plane that has been projected from one of the
principle planes but is perpendicular to only one
of the principle planes. Folding line a line
between views that might be thought of as
corresponding to a hinge in the glass box. See
the following two pages for a comparison between
a glass box containing only principle planes to
one that contains an auxiliary plane.
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Lecture 9 EGR 110 Engineering Graphics
Principle Orthographic Views - The Glass
Box Recall how the concept of the glass box was
used to illustrate the relationship between the
six principle orthographic views (top, front,
right side, left side, back, and bottom).
Unfolding the box as shown below shows the proper
orientation of the views.
Reference Page I-1 in Engineering Graphics
Workbook, Series I, by Craig Craig.
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Lecture 9 EGR 110 Engineering Graphics
Auxiliary Views - The Glass Box The modified
glass box shown below includes a side of the box
that is normal (parallel) to a plane of interest.
Unfolding the box shows the proper orientation
of the views.
Reference Page I-1 in Engineering Graphics
Workbook, Series I, by Craig Craig.
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Lecture 9 EGR 110 Engineering Graphics
Example Principle orthographic views do not
show certain features well. The block below has
an inclined plane with three holes in it.
Showing the location and size of the holes is
awkward since the holes appear as ellipses and
the inclined plane that is not shown in true
size. An auxiliary view would be helpful in this
case (see next page).
Discuss how distances are transferred across
folding lines.
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Lecture 9 EGR 110 Engineering Graphics
Example (continued) The example on the last
page has been modified to use an auxiliary view.
Note that this view shows the inclined plane and
the holes in true shape. The size and location
of the holes are more easily shown using an
auxiliary view.
Discuss how distances are transferred across
folding lines.
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Lecture 9 EGR 110 Engineering Graphics
Example Work problem AUX-2 in Engineering
Graphics Workbook, Series 1, by Craig Craig.
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Lecture 9 EGR 110 Engineering Graphics
Auxiliary Views in Inventor Creating auxiliary
views in Inventor is easy. Instead of selecting
Projected View to create a projection from an
existing base view in a drawing file, select
Auxiliary View (then select the edge view of the
surface of interest) and drag the auxiliary view
onto the drawing sheet. Try the example shown
below. Note that the right side view shows the
holes as ellipses, but they are in true shape in
the auxiliary view.