152 Exploring Drafting
Computer graphics continues to revolu-
tionize drafting and engineering, Figure 7-1.
Computer-aided drafting and design systems
play an integral part in the entire engineering
process, from design and drafting to analysis
and presentation. They aid in designing mech-
anical products, buildings, and many other
types of manufactured and constructed items.
There are many benefi to using CAD as fits fi
a design and drafting tool. Traditional drafting
tasks, such as drawing basic shapes, lettering,
and creating views, are greatly simplified with fi
the electronic tools of a CAD system. CAD pro-
grams provide setup tools, drawing and edit-
ing commands, and customization methods
to maximize accuracy and profi There ficiency.
is a wide range of programs to choose from
depending on the nature of the work. This
chapter introduces the various applications of
CAD drafting and discusses the common tools
used to create CAD drawings.
Overview of Computer
Graphics and CAD
Computer graphics was fi rst employed fi
for aerospace design in the 1950s. It is now
a required tool of industrial technology. Until
the advent of CAD, engineers, designers, and
drafters had to imagine and then evaluate a
three-dimensional object that was drawn in
two dimensions on a fl at sheet of paper. The
only way a design could be verified in three
dimensions was to make a wood, clay, plaster,
or plastic model. This is an expensive and
time-consuming process.
The emergence of CAD provided design-
ers with a dynamic new tool. CAD technology
permits more time for creative work because
it eliminates the repetitive tasks required in
traditional drafting.
CAD is a computer graphics technology
that allows users to generate and display 2D
and 3D designs electronically, Figure 7-2.
Many people are able to use a computer
drawing program after a suitable training
period. However, the principles of drafting are
fundamental to both traditional drafting and
CAD. A working knowledge of basic drafting
standards, techniques, and procedures is
absolutely necessary to be an effective CAD
drafter.
The main function of a CAD designer or
engineer is to define the basic shape of a part,
assembly, or product in 2D or 3D form. The
Figure 7-1 Computer-aided drafting systems are
used for a wide variety of applications in design
and engineering. With the proper CAD program, it
is possible to generate realistic three-dimensional
models representing complex mechanical products.
(Autodesk, Inc.)
Figure 7-2 A 3D drawing created with a typical
CAD system. With the proper tools, 2D and 3D
representations of the object being designed can be
generated. (Autodesk, Inc.)