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Chapter 10 Developing Design Solutions
sketches communicate shape and propor-
tion. They do not communicate size. For
this task, we need to add more details, and
thus, we need a third type of sketch, called
a detailed sketch. This sketch communi-
cates the information needed to build a
model of the product or structure. Detailed
sketches can also be used as a guide to pre-
pare engineering drawings for manufac-
tured products and architectural drawings
for constructed structures. Engineering
and architectural drawings are discussed
in Chapter 12.
Detailed sketches are helpful when
models of products or structures are made.
Building models requires three major types
of information. See Figure 10-11:
Size information. This information
explains the overall dimensions of the
object or the sizes of features on an
object. Size information might include
the thickness, width, and length of a
part, the diameter and depth of a hole,
or the width and depth of a groove.
Location information. This
information gives the positions of
features within the object. Location
information might establish the
location of the center of a hole, the
edge of a groove, or the position of a
taper.
Geometry information. This
information describes the geometric
shapes or relationships of features
on the object. Geometry information
can communicate the relationship
of intersecting surfaces (square or
45° angle, for example), the shapes
of holes (rectangular or round, for
example), or the shapes of other
features.
Designers often use pictorial-sketching
techniques to capture and further refine
product-design ideas. These techniques try
to show the artifact very similarly to how
the human eye will see it. Therefore, a single
view is used to show how the front, sides,
and top will appear. Designers produce
three different kinds of pictorial sketches
when refining ideas. These sketches are the
following:
Oblique sketches.
Isometric sketches.
Perspective sketches.
Oblique Sketches
Oblique sketches are the easiest pic-
torial sketches to produce. These sketches
show the front view as if a person is look-
ing directly at it. The sides and top extend
back from the front view. They are shown
with parallel lines that are generally drawn
at 45° to the front view. The depth lines may
be drawn at a different angle, such as 30° or
60°, depending on the intended result.
To produce an oblique sketch, the
designer completes steps similar to those
shown in Figure 10-12.
1. Lightly draw a rectangle that is the
overall width and height of the object.
Figure 10-11. The types of information
provided on detailed sketches are size,
location, and geometry.
Geometry
Location
Size
9/16″
25°
1 1/4″
11/16″
2″
1/4″ Diameter