Technical Drawings and Sketches, Continued
Scale
Technical sketches are not made to any scale. The size of your sketch
depends upon the complexity of the object and the size of your paper.
They
are preludes to fabrication drawings (requiring precise measurements) and
only meant to convey an overall idea. Using gridded or ruled sketching
paper helps you to draw objects to size.
Figure 4-2 shows various types of ruled papers.
Figure 4-2.—Ruled sketch paper.
Proportion
Technical sketches must be proportional. No matter how much attention you
pay to detail or how good your technique is, if the proportions are incorrect,
the image is not successful. One method of establishing proportion is to use
a small dowel or your pencil as a measuring stick representing an arbitrary
unit of measure. Begin establishing proportion by comparing height-to-width
ratios. Visually transpose that measurement to your paper. As you proceed
with the sketch, continue to compare larger areas with smaller areas using the
dowel or pencil as a ruler.
Figure 4-3 illustrates how to use a dowel or pencil as a unit of measure.
Figure 4-3.—Using a
pencil as a unit of measure.
Continued on next page
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