SolidWorks 2010 Bible

Chapter 7: Selecting Features

setup for an even more complex loft. It is helpful to envision features such as this when you are

troubleshooting or setting up sweeps that are more complex. If you open the part mentioned pre-

viously from the CD-ROM, you can edit the Sweep feature to examine the sections for yourself.

FIGURE 7.16

The sweep profile follows the path and is controlled parametrically by guide curves.

In most other published SolidWorks materials that cover these topics, sweeps are covered before

lofts because many people consider lofts the more advanced topic. However, I have put lofts first

because understanding them is necessary before you can understand complex sweeps, as complex

sweeps really are just lofts.

Pierce relation ................................................................................................

The Pierce sketch relation is the only sketch relation that applies to a 3D out-of-plane edge or

curve without projecting the edge or curve into the sketch plane. It acts as if the 3D curve is a

length of thread and the sketch point is the eye of a needle where the thread pierces the needle eye.

The Pierce relation is most important in the Sweep feature when it is applied in the profile sketch

between endpoints, centerpoints, or sketch points and the out-of-plane guide curves. This is

because the Pierce relation determines how the profile sketch will be solved when it is moved

down the sweep path to create intermediate profiles.

Figure 7.17 illustrates the function of the Pierce relation in a sweep with guide curves. The dark

section on the left is the sweep section that is sketched. The lighter sketches to the right represent

the intermediate profiles that are automatically created behind the scenes, and are used internally

to create the loft.