SolidWorks 2010 Bible

Part VII: Working with Specialized Functionality

For example, the sketch shown in Figure 31.3 cannot be fully defined without also overdefining

the sketch. The main difficulty is that the combination of the tangent arc and the symmetric legs of

the end brace cannot be located rotationally, even using the questionable reliability of 3D planes

that are discussed next. The only workable answer to this is to create a separate 2D sketch on a real

2D sketch plane, where the plane is defined by the elements of the 3D sketch.

FIGURE 31.3

Three-dimensional sketches may be difficult to fully define.

This set of sketch entities

cannot be located rotationally

within the 3D sketch

Planes in space

It is possible to create planes directly in 3D sketches. These planes work like regular planes starting
in SolidWorks 2010, where they are defined by constraints and selections rather than selecting a
type of method to define a plane. Sketches can be created on these planes, and move with the
planes. Having planes in the sketch also enables planar sketch entities such as arcs and circles in
3D sketches.

Unfortunately, there is a lot to watch out for with 3D planes, as they are called. The first thing to

watch out for is that they do not follow their original definition like normal Reference Geometry

type planes. Figure 31.4 shows the PropertyManager interface for creating 3D planes; however,

keep in mind that the plane does not maintain the original relation to these initial references. The

parent-and-child relations that SolidWorks users are used to are suspended for this one function,

or work in the reverse from what you normally expect.