Chapter 7 Computer-Aided Drafting and Design
155
discussed later in this chapter. Another way
to avoid drawing objects repeatedly is to use
blocks. Blocks are objects designed for multiple
use in drawing projects. Once something is
drawn and saved as a block, it can be inserted
Blocks
One of the basic advantages of CAD is
never having to draw the same object twice.
For example, objects can be copied and reused
once they are drawn. Copying objects is
.438
1.626
2X R1.875
2X R.750
2.250
2X ∅.938 1.125
2X R1.310
A
A
SECTION A-A
NOTE:
ALL FILLETS AND ROUNDS R.125
6X ∅.343
∅.688
B
A
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Figure 7-11. Layers are used in CAD drawings to distinguish different drawing content. A—The visible lines, centerlines,
section lines, and cutting-plane line in this drawing are on different layers. Each layer has the appropriate linetype.
The Centerline layer is assigned the color green. All other layers are assigned the color black. B—The dimension
layer is turned on to show dimensions. This layer is assigned the color red.
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