To Gather a Mill Volume
Gathering allows you to reference surfaces and edges of the design model.
1. Click > 
Mill Volume. The Mill Volume tab opens. Creo NC enables the icons for only those features that are relevant for the manufacturing model.
Mill Volume. The Mill Volume tab opens. Creo NC enables the icons for only those features that are relevant for the manufacturing model.2. Click 
Gather Volume Tool.
Gather Volume Tool.3. The VOL GATHER and GATHER STEPS menus appear. The GATHER STEPS menu has the following commands:
◦ Select—Select surfaces to be machined. Select provides multiple ways of surface selection, that are described below. All surfaces included in the volume definition are sewn together to form a single quilt, and Creo NC closes the volume automatically by extruding the boundaries of this quilt vertically up to the retract plane (or, if defining the volume at setup time, the plane selected for upward direction).
◦ Fill—Use Fill if you want to ignore the inner loops (holes, slots) on the selected surfaces. You can fill loops by individually selecting them, or by selecting a surface to fill all internal loops on it.
◦ Exclude—Use Exclude if you want to ignore the outer loops or exclude some of the selected surfaces from the volume.
◦ Close—Use Close if you want to specify ways of closing the volume, other than the default way described above.
As you modify the surface quilt and closing instructions, the volume is recalculated. The mill volume can be displayed at any time using Show Volume.
You can repeatedly redefine the volume by adding more references of a certain type, or removing certain references. Whenever you select references for gathering, the FEATURE REFS menu appears with the following commands:
• Add—Select additional references (this is the only option available when you start defining the volume).
• Remove—Clear the selection of references. Select surfaces or loops that you want to remove.
• Remove All—Clear all the selected references of the current type. For example, if the Bndry Srfs option is highlighted, clicking Remove All clears the definition of bounding surfaces.