SolidWorks 2011 Parts Bible - Matt Lombard [149]
Link values are listed under the Equations folder in the FeatureManager. Figure 10.11 shows the link values in a listed part, and the drop-down list from which you can select them or type them. Notice again that the Link Values feature also operates from a dialog box instead of the PropertyManager.
FIGURE 10.11
Link values listed in the FeatureManager, and the Shared Values interface
Note
Another way to access link values is through the Modify dialog box. If you click the down arrow at the right end of the dimension value box, you can select between Link Values and Equations. In fact, if you press the Down Arrow key on the keyboard, the Equation interface becomes available. There is no similar trick to get Link Values to appear.
You must type in the first link value that is assigned in a part. After you add the first one, you can link other dimensions to this link value by using the drop-down arrow shown in Figure 10.11. You cannot edit link values directly, which means that you cannot change a dimension from linking to a value called “height” and instead link it to a value called “length.” In order to change the value to which a dimension is linked, you must first unlink the value and then relink it. The Unlink function is available from the RMB menu in the same way that you assign link values. Dimensions that have a link value have the small chain symbol displayed to the left of the dimension. Figure 10.12 shows the Unlink option in the RMB menu.
FIGURE 10.12
Unlinking a link value
To link several dimensions to the same value at the same time, you can Ctrl+select multiple dimensions and then right-click one of them and select Link Value. It will link all the dimensions selected at once. (Thanks to Brian McElyea for this suggestion!)
Tip
One link value name has a special significance. If you use the name thickness, then a Link To Thickness option appears in all extrude dialog boxes. This is intended to reflect sheet metal functionality, but it is useful for models of various manufacturing techniques.
To take this one step further, you can save a part template with a thickness link value; all your new parts will also have this functionality right from the start. To save the template with a link value, you must create at least one dimension to assign the link value, and then delete the geometry (and the dimension); however, the link value will remain.
Link values of different types are not necessarily interchangeable. You cannot use angular dimension link values on radius, diameter, or linear dimensions. You can use linear and diameter link values interchangeably, but not angle link values.
Using Global Variables
Global variables are assigned in the Equations dialog box as simply the variable name equaling an expression or a value. Figure 10.13 shows a list of equations, link values, and global variables. When you type in a variable name, you do not need to add the quotation marks; they are added automatically. The global variable named “multiplier” uses an expression to calculate its value. The global variable shown in Figure 10.13 called “global variable” is simply assigned a value directly.
FIGURE 10.13
Equations, link values, and global variables
Global variables can be used as values in other equations, or they can be used as link values. The link value functionality has been available since SolidWorks 2007. Figure 10.14 shows the Shared Values dialog box enabling the user to select either global variables or link values when assigning a link value. Note that link values cannot be assigned through the Equations interface; they must be assigned through the Shared Values dialog box, while global variables can only be assigned in the Equations interface, not in the Shared Values dialog box. Notice that the items with the $VAR syntax are the global variables.
FIGURE 10.14