Datasheet

Polar Arrays
Geometry with a repeated angular pattern is often found in mechanical applications and
sometimes in architectural and civil applications. To create polar arrays efficiently, avoid
repeating the same set of editing operations for each feature arrayed. Start by identifying a
repeatable pattern on the object. Draw the whole pattern once, and then array the result,
rather than arraying each of the components of the pattern separately. Be careful. It’s easy
to select an extra entity when you use the Polar option of ARRAY. The result looks fine,
but you have entities on top of each other. The image in Figure 1.7 illustrates an efficient
technique for using polar arrays by identifying and creating the repeatable pattern before
arraying anything. The repeatable pattern is shown on the left, and the result of doing a
single array of that pattern is on the right. The alternative involves multiple construction
lines and six times more editing for each feature.
PEDIT
After using ARRAY to create geometry from lines and arcs, you can determine whether
the result is perfect using the PEDIT command. If you use PEDIT to join lines into a
closed object, they can only be joined if they connect perfectly at all intersections. Your
geometry is perfect if the first option of PEDIT, Close, changes to Open after you’ve joined
all your lines. If the geometry isn’t perfect (and sometimes that can’t be helped), you can
still join the segments into a single object using the MPEDIT command.
Figure 1.7
Arraying the
repeatable pattern
Because WCS is the default, you can type UCS and press the Enter key twice—once to execute
the command, and once to accept the default.
16 ■ chapter 1: AutoCAD Productivity
09939c01.qxd 12/5/06 3:59 PM Page 16