Moving into the Assembly World - Autodesk Inventor 2010: No Experience Required - page 142

The Constraint Set Tab
This is a specialized tool that can be very useful if you traditionally construct
assemblies from a common point or in relation to datum points on various parts.
By placing a User Coordinate System (UCS) in parts, you can tell those parts to
align the X, Y, and Z planes of their UCS systems in one step. This is an interest-
ing and powerful technique but beyond the scope of this topic.
Let's put together your two existing components and position them properly.
There are a few different ways you can assemble them accurately. For this exam-
ple, we'll focus on the critical feature of your product being a fan blade and the
fact that the major components are positioned around it:
1. Select the Constrain tool from the Position panel of the Assemble tab.
The fi rst thing you'll do is make the Z axis of each part line up so
that you know both parts are centered on where the blade will even-
tually be placed.
2. Expand the Origin folders for both the housing and the duct. Using a
Mate type constraint, pick the Z axis in both parts.
3. The duct snaps into place. If you have your sound on, yes, that was a
cowbell.
4. Click the OK button to accept this constraint and close the dialog box.
5. Pick and drag the duct. Note that it pivots about and can still move
along the Z axis. When you've moved the part, make sure the duct is
place behind the housing and that the face with the two holes is
toward the top, as shown in Figure 3.27.