SolidWorks 2011 Assemblies Bible - Matt Lombard [33]
Organizing mates
The Mates area remains a constant, single folder, but you can organize it by reordering the mates and grouping them into folders. Each mate is shown with a symbol corresponding to the type of mate it is, but the mate folder is shown as a pair of paper clips.
Applying assembly features
In manufacturing, once parts are assembled, secondary machining operations are sometimes applied to them to ensure that holes line up properly, or for other purposes. For example, assembly features can be cut extrudes, cut revolves, or hole features. These features appear only in the assembly, not in the individual parts.
You should not confuse assembly features with in-context features. In-context features are created when you are editing a part in the assembly with a reference between parts, but the sketch and feature definition are in the actual part.
Some new assembly features have been added to SolidWorks 2011 that don't necessarily fit the secondary operations description, such as the ability to make fillets and chamfers as assembly features.
Using component patterns and mirror components
Component patterns can pattern either parts or assemblies by creating either a pattern defined in the assembly or a pattern that follows a pattern feature created in a part. The pattern is listed as a feature in the assembly FeatureManager, and all the instance parts appear indented from the pattern feature in the design tree. You can hide or suppress each instance, change its configuration, and in most ways control it as if it were a regular part in the design tree.
Because the options for locally defined patterns are comparatively limited, users generally like to use part feature patterns to drive the component patterns when possible.
Component patterns are listed at the bottom of the assembly FeatureManager with a set of components under a LocalPattern icon. The component instances under the LocalPattern can be controlled in several ways, including through assigned configurations, colors, and display states. The pattern can even be dissolved, leaving the components but removing the intelligent pattern that places them.
Mirror components are listed under a special MirrorComponent icon after the mates.
Performance
To improve performance, it is best to pattern subassemblies if possible. If it is not possible, then patterning a group of parts is the next best option. Making multiple patterns, one for each part, is an inefficient way to accomplish the same thing.
Looking at in-context reference Update Holders
It is difficult to get a good picture of assemblies in general without including a discussion about in-context references, but to treat the subject properly, it also requires its own section, and in fact, this book gives in-context modeling its own chapter (see Chapter 10). When you create a reference between parts in an assembly, the assembly needs to remember which parts are involved in the reference and what assembly creates the spatial relationship between them.
When you create the relation, a placeholder has to remain in the assembly to hold this information. This placeholder is called an Update Holder. The Update Holders do not display by default. To see them, you must right-click the top level in the FeatureManager and select Show Update Holders. They only exist when in-context references exist in the assembly, and there is one Update Holder for each in-context sketch or feature. You cannot do very much with the Update Holders, other than query them for parent/child relations and to list the external relations, but they serve as a reminder that you have in-context references to maintain. For more information