Creating Solids and Surfaces from 2D - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 105

semicircle, and the other point of the axis is any point along the positive Z
direction ( Ortho or Polar On ). The angle of revolution is -180 degrees.
4. The first baluster is also obtained from the application of the REVOLVE
command to the vertically closed polyline. The axis is defined by both en-
dpoints of the vertical segment and the angle is 360 degrees.
5. To create the other balusters, apply the ARRAY command, specifying
Polar , the center at the midpoint or center of semicircle element, 11 ele-
ments, angle to fill -180 degrees, and rotating objects as they are copied.
Note
Since Version 2012, the ARRAY command changed considerably, so
for these situations the ARRAY command is faster. With Version 2013,
we could also apply the new ARRAYCLASSIC command, which is the
same as the ARRAY command in versions prior to 2012.
6. The two balusters at the ends are erased. We could also apply the SLICE
command (presented in Chapter 7 , Editing Solids and Surfaces ) to cut
half of each one.