Geoff,

The curves now look good, and since the plunge for a ball mill is only 1/2D, I see very little problems with it. The old way, with the cut starts below the surface would have automatically allowed the use of the plunge rate, but it was very confusing to look at and understand. Maybe I should bow my head and say, "sorry". You might want to make those lead-ins an option. (urk!)

The jaggies are still there, even when using a ball mill.

The odd full-circular paths 'above the plane' are still there when depth=radius in a curved pocket.

In my quick test, the Seed line is 2" long, starting at -1,0 and extending to +1,0.

Depth selected is -1 -- so it has a depth exactly equal to the curve's radius.

Ball nose cutter, diameter 0.375"

Stepovers and depth increments of 0.040"

angle of 5

I am confused by one thing. I fired up your plugin, and the Edit/Intersection Points function became wonky. It would show intersection points that did not exist. For instance, select the outermost toolpath created by my test example above. Without selecting any other lines, do an Edit/intersection points, and one will show up at the begin and end points of the line. If you rotate the whole array of created curves along X in order to view the lines in the XY plane, it gets even stranger. Then, intersection points show up at approximately -1/2D (almost where the vertical leadins stop, but not exactly there). But since these are polylines, there are no 'intersections' there.

Lloyd