SolidWorks 2010 Bible

Part II: Building Intelligence into Your Parts

is perfectly acceptable, as is

1+1/2

or

1 1/2

In the second case in this example, the plus symbol is understood.

Other types of operations are also available, such as ones for changing units in a dimension box.

For example, if you are editing a part in inches, and enter 40mm, then SolidWorks does the

conversion for you. You can even mix units in a single expression such as 4.875+3.5mm, where

the inch part is assumed as the document units.

SolidWorks does not remember the expression itself, only the final value. Expressions can be

entered into any place where you enter dimensions for SolidWorks features.

Tutorial: Using Equations

Follow these steps to get some practice with using equations:

1. Start from the part on the CD-ROM with the filename Chapter9 Tutorial
   Start.sldprt.


2. Show the dimension names. Choose View ➪ Show Dimension Names to find this setting.


3. Double-click the Circular Pattern feature to display the angle and number of
   instances of the feet and related features. You may have to move the angle dimension
   to see the pattern instance number.


4. Click the instance number. Change the name of the dimension to # (pound or number
   sign) in the Dimension PropertyManager. Make sure that Instant3D is unselected when
   doing this.


5. Double-click the first feature, which is the revolve, and rename the 3.60-inch
   dimension CapRad, again by selecting it and using the PropertyManager.


6. Write an equation that drives the number of legs by CapRad/7.

a. Open the Equations dialog box by choosing Tools ➪ Equations.

b. Click Add to add an equation.

c. Double-click the Circular Pattern and click the # dimension. Make sure that the name
of the dimension is listed in the equation box, and type an equal sign.

d. Double-click the Revolve feature and select the CapRad dimension; then type the
characters /1.5.

e. Add a comment to the equation to reflect which dimension is driving which dimension.