SolidWorks 2011 Assemblies Bible - Matt Lombard [95]
Deciding whether to use mating or in-context
In-context is initially so fast and easy to use that it can be addictive, but you need to think before you use it because of the speed and file management implications these relations will have later on in your design process.
Communicating design intent
If someone else needs to use your model after you are done with it and possibly edit it, then you should leave some clues to help this person understand how the model works, and how it is best changed. For example, you can use descriptive feature and sketch names, comments that are associated with features, the Design Binder to add documentation, and the Design Journal to write notes. You can even put HTML (Hypertext Markup Language) links in notes that display in the graphics window.
In-context design intent may not always be obvious, and an impatient user may find it more expedient to delete the in-context references and replace them with either local relations or no relations at all. The more you document your intent, the more likely others will be to follow it.
Using Other Types of External References
The external reference symbol (->) indicates in-context features that have been created in the context of an assembly, but it also indicates three other types of external references: inserted parts, split parts, and mirrored parts.
Using inserted parts
In the past, inserted parts have also been called base parts and derived parts, and some users and even SolidWorks sometimes still use those names. (For more information on inserted parts, see Chapter 19.)
An inserted part is simply an entire part that has been inserted into another part. This is sometimes referred to as a pull operation because the data is pulled from the original part into the child part. The part may be inserted at any point in the history of the design tree, and it may create an additional body within the part or be added to the existing one. Additional features can also be added to the inserted part.
Items that can be brought along with the inserted part are solid bodies, surface bodies, planes, axes, sketches, cosmetic threads, and even features. You can also use a particular configuration of the inserted part in the child part. (For more information, see Chapter 14, which deals with configurations, and also Chapter 19, which deals with master models.)
You can use inserted parts for many modeling applications, such as cast parts and secondary operations. You first insert the original cast part into a new blank part. Then you add cut and hole features until the part resembles the finished part.
Another application for inserted parts is a single part that has been built from several models. An example might be a large, rather complicated plastic basket, where the basket is modeled as three individual parts, and then reassembled into a single part. Another application may be to insert a part as a body into a mold block to create a mold cavity. To insert a part into another part, you can choose Insert⇒Part.
Working with split parts
Inserted and split parts are both master model techniques, as are a few more techniques that are discussed in Chapter 19. Some people also include in-context techniques with the master model tools because this is a way of making several parts update together.
Split parts are sometimes called a push operation because the data is pushed from the original multi-body part to the individual child parts. The split function takes a single body and splits it into several bodies, optionally saving the bodies out as individual parts. This is done for various reasons, such as creating a single, smooth shape out of several different parts — for example, automobile body panels or the various covers and buttons on a computer mouse. You can use the split