DRAFTING

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DRAFTING THE UNIVERSAL LANGUAGE
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SKETCHING
Rough Sketches are the most common recording
method. The term rough describes the state of
the design ideas. It suggests that the designs
are incomplete and unrefined.
Refined Sketches are refined design ideas. They
may not look anything like the original rough
sketches.
Detailed Sketches communicate size, in addition
to the shape and proportion communicated in the
first two drawings. It also communicates the
information needed to build a model of the
product or structure.
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Developing Pictorial Sketches
Different techniques are used to show the
artifact as the human eye would see it.
Therefore, a single view is used to show how the
front, sides, and top would appear.
Isometric Sketches
Oblique Sketches
Perspective Sketches
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OBLIQUE SKETCHES
The easiest pictorial sketches to produce.
Show the front view as if you were looking
straight at it.
Sides extend back from the front view.
Sides shown with parallel lines that are
generally drawn at 45 degrees to the front view.
Cavalier oblique drawings cause the sides and top
to look deeper than they are.
Cabinet oblique drawings shorten the lines that
project back from the front to one-half their
original length.
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ISOMETRIC SKETCHES
Isometric means equal measure.
Angles formed by the lines at the upper right
corner are equal to 120 degrees.
Object is shown as if viewed from one corner.
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PERSPECTIVE SKETCHES
Show how the human eye and camera would see it.
Realism is obtained by having parallel lines meet
at a distance vantage point.
Most realistic, yet, most difficult of the three
sketches.
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TYPES OF PERSPECTIVE VIEWS
Three major types one-point, two-point, and
three-point.
One-point perspective shows an object as if you
were directly in front of it.
Two-point perspective shows how an object would
appear if you stood at one corner.
Three-point perspective shows how the eye sees
the length, width and height of an object.
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Detail Drawings
Most are prepared using the multi-view method.
This method places one or more views of the
object in one drawing.
Generally, a top, right side, and end view are
shown.
Multi-view drawings use orthographic projection
to project information at the right angles to new
views.
Front view is drawn in the lower left quadrant of
the paper.
Projection lines are extended to the top and
right of a front view to form the top and side
views.
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DRAWING LINES
Different lines are used to show the outlines and
major details on an object.
Object lines are the darkest lines which show the
outlines and major details.
Hidden lines are dotted lines used to show
outlines which are not visible in a certain view.

Center lines locate holes in a part. These lines
pass through the center of the hole.
Extension lines, used in dimensioning, indicate
the points from which the measurements are taken.
Between the extension lines are the dimension
lines. These have arrows pointing to the
extension lines that indicate the range of the
dimension.
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GLOSSARY
Rough sketches- incomplete and unrefined design
ideas. Refined sketches- refined design
sketches. Detailed Sketches- communicate size, in
addition to the shape and proportion communicated
in the first two drawings. Oblique sketches-
Shows the front view as if you were looking
straight at it, and the sides extend back from
the front. Parallel lines drawn to 45 degrees to
the front view. Isometric sketches- shows
object as if viewed from one corner. Angle
measures in upper right corner are equal to 120
degrees. Perspective sketches- realistic sketches
that have parallel lines that meet at a distance
vantage point.
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GLOSSARY
One-point perspective- shows an object as if you
were directly in front of it. Two-point
perspective- shows how an object would appear if
you stood at one corner. Three-point perspective-
shows how the eye sees the length, width and
height of an object. Multi-view method- a
method that places one or more views of the
object in one drawing. Orthographic projection-
top and side views are projected up to the right
of the front view. Object lines- are the darkest
lines which show the outlines and major
details.
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GLOSSARY
Hidden lines- dotted lines used to show outlines
which are not visible in a certain view. Center
lines- lines that locate holes in a part and pass
through the center of the hole. Extension lines-
lines used in dimensioning, indicate the points
from which the measurements are taken. Dimension
lines- lines that have arrows pointing to the
extension lines that indicate the range of the
dimension.