Chapter 3 Communicating Design Ideas
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Drawing Techniques
Sketches are drawn freehand, with or without grid paper. To create a
more accurate orthographic drawing, you can use plain paper and drawing
instruments. The instruments most often used are the T-squares, 45° and
30°/60° triangles, compass, and scale (ruler). Techniques for drawing with
these instruments include:
• As a general rule, when drawing lines with a T-square, draw in the
direction the pencil is leaning, as shown in Figure 3-27.
• When drawing vertical lines with a drafting triangle, lean the pencil
away from you and draw the lines from bottom to top. See Figure 3-28.
• When using a 45° or 30°/60° triangle, draw lines in the directions
shown by the arrows in Figure 3-29.
• Hold a compass between the thumb and forefinger and rotate
clockwise. Lean the compass slightly in the direction of the rotation
as you draw a circle, as shown in Figure 3-30.
gure 3-30. When using a compass, draw
circles or arcs lightly at first. Make repeated
turns to darken the line.
gure 3-29. Draw sloping lines using a
triangle, as shown here.
gure 3-28. Note how the pencil is held to
draw vertical lines using a triangle.
gure 3-27. Draw in the direction the pencil
is leaning.