SolidWorks 2010 Bible

Part II: Building Intelligence into Your Parts

To build the equation, first click the Equation button on the Tools toolbar to open the Equations

dialog box. Then click the Add button to display the Add Equation dialog box. To add dimensions

to the equation section, just select the dimension. You can use the keypad on the dialog box or on

your keyboard to add operators and syntax. All standard rules of syntax apply for the order of

operations, use of parentheses, and driving versus driven sides of the equation.

Using comments ............................................................................................

Notice the comment to the right of the first equation in Figure 9.5. Comments can be very useful

for annotating equations for yourself or others. Two important reasons to annotate are to remember

the significance of variables or dimensions and to add special notes about the logic of the equation.

You can make comments for equations by using a single quote after the end of the equation, or

by clicking the Comment button in the Add Equation dialog box. In the following example, the

comment, “This must be solved first,” is applied to the equation using the single quote before the

comment.

“Spacing@LPattern1” = “Length@Sketch1” / (“Instances@LPattern1”)

‘This must be solved first

To expand on the earlier discussion about projected changes to the Equation interface, several

standard selection functionalities do not work in the Edit Equation dialog box. These include

triple-clicking to select all (although double-clicking works to select a single word) and pressing

Ctrl+A to select all.

Tip
You can make general comments for the model in the Design Journal, a Microsoft Word document that is
embedded into the SolidWorks file. The Design Journal is found in the Design Binder folder near the top of the
FeatureManager. n

On the CD-ROM
You can find the part used in this section on the CD-ROM with the filename Chapter 9 Equations.sldprt. n

Using driven dimensions

Sometimes it is more convenient to use a driven (reference) dimension in an equation. This is

particularly true when using geometry is the best way to calculate a number. For example, if you

are manufacturing a helical auger in 90-degree sections from flat steel stock, then you need to

design the auger in 3D, but begin to manufacture it in 2D.

What is the shape of the auger when flat? The best way to figure this out (aside from lofted bends,

which are discussed in Chapter 29) is to use a little high school geometry, a construction sketch,

and some simple equations.