Alignment Constraints
- On the Project Tree, open the Analysis Workbench.
 - 
                On the Analysis Workbench toolbar, click 
 (Alignment).
             - 
                In the modeling window, click to select faces of
                    specific parts on the model.
                Note: Selected faces must be cylindrical. Your selections will appear in the Alignment dialog.
 - 
                Click OK.
                The alignment will appear in the Project Tree. If selected, it will be visually represented in the modeling window.