To Add a Cut Line

In the Setup Cut Lines area, on the Cut Lines tabbed page of the Cut Definition dialog box, select a Cut Line Style option (Open Ends or Closed Loops) and click Add.

The Add/Redefine Cutline dialog box opens.

From Edges—Define the cut line by selecting edges either on the surfaces selected for milling, or on some other surfaces (specified using the Tool Extent or the Alternate Surfaces option).
From Curves—Define the cut line by selecting preexisting datum curves.
Projected—Sketch the cut lines in the retract plane (or specify another sketching plane). The system will project the sketched cut lines onto the surfaces to be machined. The projection direction is parallel to the z-axis of the NC Sequence coordinate system.
From Surfaces—Define the cut lines using surface boundaries. You will be prompted to select the surfaces using the SELECT SRFS menu options and then enter the offset value for the surface boundaries. This option appears for 4- and 5-Axis machining only.

Depending on the selected Cut Line Type option, select the edges, datum curves, surfaces, or sketch the cut lines.
For Open Ends cut lines, if you use From Curves or Projected, you can adjust the endpoints of the cut line by clicking Specify Ends.
For Closed Loops cut lines, click the Select Start Point button and select on the cut line to specify the start point for machining. If you select somewhere along a cut line entity (other than at an endpoint), you will be prompted to specify the placement of the point as a length ratio along the selected entity. The options in the ENTER VAL menu are:

Click Preview to verify the cut line.
When satisfied, click OK. The system lists the name and the type of the newly defined cut line in the list box in the Setup Cut Lines area on the Cut Lines tabbed page of the Cut Definition dialog box.