SolidWorks 2011 Parts Bible - Matt Lombard [157]
FIGURE 11.14
Using the Custom Properties tab to assign custom properties
Using derived configurations
Derived configurations are configs that are dependent on other configs. You can create them from the RMB menu on a configuration, and they appear indented underneath the parent config. Figure 11.15 shows the RMB menu and the position of the derived config in the tree.
FIGURE 11.15
Creation and placement of the derived config
Derived configurations maintain the same values and properties of the parent config unless you break the link to the child (derived) config by explicitly changing a value in the child config. For all other values, the child config value changes when the parent config value changes.
One very nice application of derived configs is to use them for simplified configurations, and set the properties so that any features that are added to the parent config are also added to the derived config. You can do this by deselecting the Advanced Option Suppress Features to Off in the PropertyManager for the configuration. This causes the derived config to inherit only features that are added to the parent, and not to other configs. You can use the simplified configs for Finite Element Analysis (FEA), making drawings of models where all of the edge breaks have actually been modeled. You can also use them for the reverse (a complex config rather than a simple one) to have a config that includes fillets for rendering purposes that are otherwise not there. In addition, you can create and maintain derived configs using design tables, which are discussed in the next section.
Understanding how file size affects speed
A long-standing dispute has raged over the effects of file size on speed. Here are the facts: When SolidWorks creates a configuration, it stores information about the 3D geometry and a preview thumbnail of the configuration inside the part file. This makes it faster to access the configuration the next time because it has only to read the data, rather than read other data and then recalculate the new data. As a result, saving the stored data makes the file larger but also enables you to avoid having to recalculate it.
Many people assign more importance to file size than I do, and use it as a criterion on which to base decisions about which features or techniques to use or not use. If I can use a single file instead of multiple files by using configurations, I prefer the single file technique, even though it is guaranteed to produce larger files, and in some cases much larger files. Libraries of parts can often be made more manageable by using configured parts rather than many individual parts. Large hard drives for storage are cheaper and easier to upgrade than processors. In the end, reading stored data rather than recalculating it is faster. This is why when SolidWorks can store data that will probably be needed again at some point, it is useful to take advantage of the single-file technique. Storage space is cheaper than rebuild time. The result is that configurations definitely increase file size.
The ideal situation would be if SolidWorks would give users control over which data is stored in model files. This is a good place for an enhancement request.
Performance
File size has a negative effect on speed when you are sending data across the Internet or working across a network. If the data is on your hard drive, then storing data instead of calculating it offers a big benefit. If you are sending data across a slow network connection, you should take measures to decrease the size of the file before sending it, such as using a zip or compression utility.
Controlling dimensions
Controlling dimensions with configurations is simple. You need only three things to start: one dimension and