Building the Foundation of the Design - Autodesk Inventor 2010: No Experience Required - page 64

Controlling a Sketch Using Dimensions
In the previous exercise, you reviewed the constraints that were added automati-
cally to the geometry of the sketch. In this exercise, you'll use both dimensions
and constraints to complete the sketch for the fi rst feature of your part:
1. Press F8 to make the sketch constraints visible again.
2. Right-click away from any sketch geometry, and select Show All
Degrees of Freedom from the Context menu.
In addition to the constraint icons, you should now see a collection of arrows.
The line segments have some restricted movement. The lines constrained to be
horizontal can only move vertically. The opposite is true for vertical lines. And
the points in the corners can move in any direction on the sketch plane. See
Figure 2.11 for a reference.
FIGURE 2.11 DOF symbols help you understand how geometric constraints limit
sketch flexibility.
When you create a new component or assembly, Inventor automatically inserts
the XY, XZ, and YZ planes as well as the X, Y, and Z axes. I have the intersection
of those axes automatically projected in to my sketch. The fan blade is the center
of the design. This blade will turn on about the Z axis. To make it easier to main-
tain spacing, you'll use the Origin planes as a reference when placing components
in the assembly. Although I don't always use the origin as a common reference,