Working with Solid Models and Weldments - Autodesk Inventor 2010: No Experience Required - page 161

FIGURE 4.6 Previewing the Rectangle feature
The next step could be done a couple of different ways, but we'll take this
opportunity to look more closely at Work features. You created a work plane in
the process of defi ning a new sketch in the last chapter, but you can use them
many ways.
Work Features
You always start a sketched feature with a sketch on a plane or planar face.
Many placed features depend on placement using a plane or planar face. A part
has three origin planes, but sometimes you need to create a sketch or place
geometry for which no planar face is available and the origin planes aren't in
the right place. In these instances, you can create a feature called a work
plane that works as a platform.
The work plane is one of three Work features; the work axis and work point
are the others. These three features are ways to build a foundation for other fea-
tures of a part. In and of themselves, they don't build the part.
You can defi ne a work plane several ways. It can be offset a distance to another
plane or face; or you can create it by defi ning a cylindrical face and either another
plane, face, axis, or edge to build a plane tangent to the cylindrical face. It can
be built based on two axes (or edges) that lie in the same plane, based on an axis
and a point, or by selecting three points. You can also place a work plane normal
to a path in a sketch by clicking the endpoint of a line or curve and then the
curve. The most important thing to keep in mind is that the work plane is asso-
ciative to the geometry that you use to defi ne it.