During my experiments with the drag knife, I discovered that the work surface must be as flat as possible.The average thickness of a sheet of paper is only about 0.1 mm. Even the slightest unevenness can therefore determine the success or failure of a cut.
Since it is not always easy in practice to ensure such a high degree of flatness, I have added a feature to my software V6.39 that detects and compensates for such deviations.
As an interesting side effect, this feature also makes it possible to perform various milling operations, such as cut or pocket machining, with precision even on uneven surfaces.