Page 107 - Mastering SolidWorks

|
76 CHAPTER 3 Working With SketcheS and reference geometry

The Stretch sketch tool is intended for use in sketches where there are enough dimensions to
make a particular change difficult by changing dimensions only. Stretch enables you to specify a
change that will change several dimensions simultaneously. Figure 3.17 shows the sketch being
stretched. Notice one of the lines is not selected at the top, so the top vertical line becomes angled
and loses its vertical relation.

Figure 3.17
Using the Stretch
sketch tool

TIP the main ideas to remember with the Stretch tool are that it is used to stretch dimensioned lines
and that you need to select the lines that will lengthen or shorten as well as the lines that will move.
Because of this, selecting entities for Stretch is best done with the right-to-left window selection or
the lasso, which also selects any items that the selection box crosses. (Left-to-right window selection
selects only items that are completely within the selection box.)

The Move, Rotate, Copy, and Scale sketch tools operate on selections within a sketch. You can
use these tools with pre- or post-selection methods. These tools delete existing sketch relations
when necessary to accomplish the task. For example, if you want to move a rectangle connected
to the origin, the Move tool deletes the coincident relation between the sketch endpoint and the
origin. If you want to rotate a rectangle, the Rotate tool deletes all the horizontal and vertical
relations on the entities being rotated. This operation may result in a completely underdefined
sketch. SolidWorks does not warn you that sketch relations are being deleted.
If you use the Scale tool on a fully defined sketch, SolidWorks scales the position of the
selected entities, deleting sketch relations if necessary to do so, but no dimensions are scaled
or deleted.

CAUTION Be careful when using these sketch tools. they can delete sketch relations without warn-
ing. Some of the tools have a check box for keep relations.

These sketch tools were originally put in the software to avoid some of the complexities and
limitations of the Modify Sketch tool, which can also move, copy, rotate, and scale sketches.