SolidWorks 2010 Bible

Part I: SolidWorks Basics

The third technique locks you into the horizontal orientation because of the orientation of the

selected lines.

FIGURE 3.1

Selection options for linear Smart Dimension

Dimension value Drop-down arrow

OK

1

2

3

Cancel

Rebuild/

No exit

Change sense

Increment value

Mark for import

Spin arrows

Spin wheel

Note
In some situations, you may run into lines that appear to be parallel but are not exactly so. This will result in an
angle dimension instead of a linear dimension. Here, you can select one of the lines and one endpoint.
SolidWorks requires parallelism be precise, and situations where lines aren’t exactly parallel happen if the
angular measurement is off in the second or third decimal place, measuring in degrees. Imported 2D drawings
and reverse engineered 3D models can be particularly susceptible to this type of error. n

Caution
When you select lines to establish a dimension instead of endpoints, both of the lines gain an implied parallel
relation that prevents them from moving as you might predict. In the example shown in Figure 3.1, neither of
the end lines can be angled unless you remove the dimension.

Another issue with adding dimensions to lines is that if you delete either line, the dimension is also deleted.
This is not true for the first and second techniques, where as long as the endpoints remain, the dimension
remains. n

You can change Smart Dimension values several ways. The most direct way is to simply key in a

value such as 4.052. The software assumes document units unless you key in something specific.

You could also key in an expression, even with mixed units, such as 8.5 mm/2+.125 or 25.4+.625

in. You can also key in negative dimensions, which function the same as the Change Sense button

in the Modify box.