Figure 5-26.-Use of an auxiliary section.
Figure 5-27.-A. Multi-view view of block in normal
position; B. Multi-view view of block revolved 30 degrees
on axis perpendicular to vertical plane.
regular planes of projection. An auxiliary view
is one that is projected on a plane other than one
of the regular planes.
A rectangular object is in normal position
for regular multi-view orthographic projection
when each of its faces is parallel to one regular
plane of projection and perpendicular to the other
two. This is the case with the object shown in
figure 5-27, view A.
USE OF REVOLUTIONS.— In a REVOLU-
TION, the object is projected on one or more of
the regular planes of projection. However, instead
of being placed in normal position, the object is
revolved on an axis perpendicular to one of the
regular planes.
Figure 5-27, view B, is a three-view multi-view
projection showing the block in 5-27, view A, as
it would appear if it were revolved 30 degrees on
an axis perpendicular to the profile plane of
projection. Figure 5-28, view A, shows how the
Figure 5-28.-Use of revolution on axis perpendicular to
(A) horizontal plane and (B) vertical plane.
5-17
