I cannot find why the start of the cut is different for "Ruff undercut 1" and "Ruff undercut 2". (I know Ruff is spelled Rough, something I do to recognize my programs.) Ruff undercut 2 is the result I want. I've tried copy/paste. Tried just changing Ruff undercut 2 by picking different items in the geometry tab.
Be as humble as your skills require you be.
