216 Exploring Drafting
Projecting Points
and Edges
It is essential that the beginning drafter
learn to properly use orthographic projec-
tion to project points and create views in
multiview drawings. Each view will show
a minimum of two dimensions. The front
view will show the overall width and overall
height, the side view will show the height
and depth, and so on. Also, any two views
of an object will have at least one dimension
in common. For example, the front and side
views will both have the overall height of the
object in common.
The process of using orthographic projec-
tion in creating the views of a multiview
drawing is known as blocking in the drawing.
This process can save much time and elimi-
nate many measurement errors. A good rule
to follow when blocking in a drawing is to
measure each distance one time, double-check
the measurement for accuracy, and project the
distance to the adjacent view. Do not “double-
measure” distances. In other words, if a
particular feature has a height of 1″, do not
measure that inch distance in the front view
and then remeasure the same distance in the
side view. Measure once and project. This rule
should be followed for each measurement. If
an object has seven different measurements
Preferred Avoid
Figure 9-15 Views showing a large number of hidden lines are used only if absolutely necessary. Too many
hidden lines tend to make the drawing confusing.
Lines meeting object lines
or other hidden lines
Lines do not
meet or cross
Figure 9-16 Correct uses of hidden lines.