188 Section 2 Drafting Techniques and Skills
Using the Rotate Command
(CAD Procedure)
A plane fi gure can be transferred to a new fi
location by using theCopy command. If you need
y
to rotate the fi gure to a different orientation, you fi
can use the
Copy
and
y Reference
options of the
Rotate
command. The procedure is similar to
that used when transferring an angle.
1. Polygon ABCDE is the given plane fi gure. fi
Refer to Figure 6-38A. The polygon is to
be transferred and rotated.
2. Enter the
Line
command and draw Line
A′B′ A A in the desired position and rotation.
Refer to Figure 6-38C.
3. Enter the
Rotate
command and select
the polygon. Specify Point A as the base
point of rotation.
4. Enter the
Copy
option when prompted
for a rotation angle.
5. Enter the
Reference
option. Pick the
endpoints of Line AB.
6. Enter the
Points
option. Pick the end-
points of Line A′B′. A A This establishes the ′
desired angle of rotation and draws the
new polygon.
7. Enter the
Move
command to relocate the
duplicated polygon. Select Point A as the
base point and specify Point A′ A A as the
second point. Erase Line A′B′ A A after mov-
ing the polygon.
Transfer a
Plane Figure
CAD
Using the Triangle Method
(Manual Procedure)
Plane figures with straight lines can be fi
transferred to a new location by using the
triangle method. The transferred figure can fi
also be rotated.
1. Polygon ABCDE is the given plane
figure, fi Figure 6-38A. The polygon will be
transferred and rotated.
2. At Point A, draw Lines AC and AD to
form triangles, Figure 6-38B.
3. Using Point A as the center, draw an arc
outside the polygon cutting across the
extended lines.
4. Draw Line A′B′ A A in the desired position
and rotation, Figure 6-38C.
5. Draw an arc with a radius equal to R′ R R and
the vertex at Point A′ A A . (Note that R = R′ ′ R R .) ′
6. Draw Arcs 1′ , 2′ ′ , and 3′ ′ to locate the triangle ′
lines. (Note that 1 = 1′ , 2 = 2′ ′ , and 3 = 3′.) ′ ′
7. Set off distances A′C′ A A , A′D′ ′ A A , and A′E′ ′ A A equal
to AC, AD, and AE.
8. Draw straight lines to form the trans-
ferred plane figure (Polygon A′B′C′D′E′). fi A A
Figure 6-38. Transferring a given plane fi gure to a new location. The transferred fi gure in this example is rotated.
A D
E
C
B
A
A
D
E
E'
3'
D'
C'
I'
B'
R'
A'
2'
C
B
2
I
3
R
B C