NX Create a Central Curve for Rough Tube Machining on an Impeller

Creating a usable "Central Curve" to rough out the windows between impeller blades.

Please see the attached video.

Step 1 - extract a face on either side of the window opening.

Step 2 - Create a Bisector Surface between the newly extracted faces.

Step 3 - Create an Isoparametric curve to represent the central curve.