Tip: Combining Sketch and Trim
A sketched section does not have to correspond exactly to the desired Mill Volume. It can be sketched larger than needed, and then "trimmed to size" using:
• The Trim option—To subtract the reference model from the sketched volume.
• The TRIM_TO_WORKPIECE parameter—To confine the volume to be milled to that inside the workpiece boundaries, in order to avoid air machining.