Please have a look at the attached file.  I've been beating my head against a wall for hours trying to get the undercut (Operation #9) to work properly.  Depending on settings (I've tried many), either the tool doesn't fully cut the profile or it gouges.  What am I doing wrong?  The -Z portion of the profile (Operation #8, not undercut) works fine.  MC2018 2.5 axis.  Thanks! Undercut_surface.mcam