SolidWorks 2010 Bible

Chapter 7: Selecting Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Best Practice
SolidWorks works best with well-disciplined sketches that follow the rules. Therefore, if you plan to use sketch
contours, you should make sure that it is not simply because you are unwilling to clean up a messy sketch.

When you define features by selecting sketch contours, they are more likely to fail if the selection changes
when the selected contour’s bounded area changes in some way. It is considered best practice to use the nor-
mal closed loop sketch when you are defining features. Contour selection is best suited to “fast and dirty” con-
ceptual models, which are used in very limited situations. n

There are several types of contour selection, as shown in Figure 7.4.

FIGURE 7.4

Types of contour selection

The terminology used by SolidWorks is not always logical, for example, the heading of the

PropertyManager panel that you use is called Selected Contours, but the item in the selection box

is called a Region. This is why you may sometimes hear Contours referred to as Regions.

3D sketch

You can make extrusions from 3D sketches, even 3D sketches that are not planar. While not neces-

sarily the best way to do extrudes, this is a method that you can use when needed. You can establish

direction for an extrusion by selecting a plane (normal direction), axis, sketch line, or model edge.

When you make an extrusion from a 3D sketch, the direction of extrusion cannot be assumed or

inferred from anything — it must be explicitly identified. Extrusion direction from a 2D sketch is

always perpendicular to the sketch plane unless otherwise specified.