SolidWorks 2011 Assemblies Bible - Matt Lombard [92]
Figure 10.19, at the top, shows the first table and points out the in-context relations. At the bottom, the large bracket appears for the machine that is mounted to the tabletop using more in-context relations. The External References dialog boxes for the two different in-context features appear in Figure 10.20. Notice that the Assembly fields at the top of the External References dialog boxes are different. You can only achieve this by selecting the Allow Multiple Contexts for Parts When Editing in Assembly option shown in Figure 10.18.
Note
The Tools⇒Options setting for multiple contexts is a system option. This means that either this option is on or off for every document on a single machine, but when the assembly is used on another machine, the option may be off.
Multiple context modeling should be the exception rather than standard practice. If you do not have all the assemblies open where the in-context references were created, then you will have some out-of-context references. This can make for a troubleshooting nightmare if someone ever has to try to reconstruct how the assembly is driven.
Best Practice
The best practice is to avoid creating multiple-context references. If you need to do this, then be very careful about naming files, and remember to turn off the multiple-context option when you have finished creating the reference.
FIGURE 10.19
Using multiple contexts
FIGURE 10.20
External References dialog boxes
If you receive a multiple-context part from someone else, the best thing to do is to determine whether you have all the files required to make it work. Right-click the external reference symbol and select Edit In Context to determine whether SolidWorks can find the right files. Also looking for an out-of-context symbol will tell you if any of the necessary files are not currently open.
Aside from doing some programming, the only way to find out whether a part was created as a multiple-context part is to examine the External References list for each in-context feature. This can be very time-consuming. Although multiple-context parts should be very rare, it is impossible to determine ahead of time whether a part that you have received is a multiple-context part, at least without programming. The one exception to this is when some features are in-context and some are out-of-context.
Using in-context with configurations
On the surface, mixing in-context references with configurations sounds like it is combining two powerful techniques that should offer you great control over models. Although this may sometimes be true, you need to be aware of some of the effects that combining these two techniques may cause. In particular, you should be careful about part configurations, particularly configurations of the referenced part.
If you are using in-context relations to parts with configurations, then you may want to consider a few things. First, look at the door-hinge part shown in Figure 10.21. At the top are three configurations of one of the hinge plates. The second hinge plate is built in the context of the assembly so that it will always match the first plate. At the bottom are the results of changing the first hinge-plate part configuration in the assembly. This looks like an ideal situation because the second hinge plate always changes to match the first hinge plate. What could be wrong with this?
The problem here is that you can only show the size of the second hinge plate that corresponds to the configuration of the first plate that is active in the assembly. If you had two instances of the hinge assembly in a top-level assembly, then you would be able to show only one size for the second plate.
A second situation where combining in-context references and configurations can cause you trouble is if you have referenced the edges of a part from another part, and a configuration of