Page 321 - Mastering SolidWorks

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Working With 3d PAtternS 293

The pattern of the rectangular bosses cannot use Geometry Pattern because the face that is
merged is not merged in all pattern instances. The pattern of truncated cylinders shown on the
same part as the pattern of rectangular bosses can use Geometry Pattern because the flat face is
merged in every pattern instance. The circular pattern in the image to the right in Figure 9.9 also
allows Geometry Pattern for the same reason.
In some situations, SolidWorks error messages may send you in a loop. As shown in
Figure 9.10, one message may tell you that the pattern cannot be created with the Geometry
Pattern turned on, so you should try to turn it off.
When you do that, you may get another message that says the pattern will not work and that
you should try to use the Geometry Pattern setting. In cases like this, you may try to use a
different end condition for the feature that you want to pattern or change the selection of features
patterned along with the feature, such as fillets. You may also try to pattern bodies or even faces
rather than features. These last two options are covered in the following sections.
Figure 9.10
geometry Pattern
error message

Patterning Bodies
I cover multibodies in depth in Chapter 31, “Modeling Multibodies,” but I will briefly discuss the
topic here. No discussion of patterning is complete without a discussion of bodies.
SolidWorks parts can contain multiple solid or surface bodies. A solid body is a solid that
comprises a single contiguous volume. A surface body is different—think of it as a sheet knitted
together from several faces that does not have the requirement to enclose a volume—but it can
also be patterned and mirrored as a body.
There are both advantages and disadvantages to mirroring and patterning bodies instead of
features. The advantages can include the simplicity of selecting a single body for mirroring or
patterning. In cases where the geometry to be patterned is complex or there is a large number of
features, patterning bodies also can be much faster. However, in the example used earlier
(Table 9.1) with patterning features in a 20 × 20 grid of holes, when done by patterning a single
body of 1″ × 1″ × 0.5″ with a 0.5″ diameter hole, patterning bodies gives a rebuild time of about
60 seconds with or without Verification on Rebuild. The function that combines the resulting
bodies into a single body takes most of the time. This means that for large patterns of simple
features, patterning bodies is not an efficient technique. Although I do not have an experiment in
this chapter to prove it, it seems intuitive that creating a pattern of a smaller number of complex
bodies using a large number of features in the patterned body would show a performance
improvement over patterning the features.
Another disadvantage of patterning or mirroring bodies is that it does not allow you to be
selective. You cannot mirror the body minus a couple of features without doing some shuffling of
feature order in the FeatureManager. In addition, the Merge Bodies option within the mirror