The Machine Setup item in the CAM tree allows you to assign a SolidWorks Coordinate System entity to define where the origin of the part is located. This is critical to creating correct toolpaths and NC programs. To learn how to create the Coordinate System please view the Solidworks Help system.
To assign the Coodinate System, right-click Machine Setup under Turning Stock in the CAM tree tab.
Click Re/Select. Select a pre-defined Coordinate System. Click 
.
Notice that the 
red plus symbol next to Machine Setup is no longer visible. 
The part origin is now defined. You are ready to load a machining feature.
NOTE: To rename the Coordinate System, double-click in the Selected Items box and type a name. Click .