1. Min Arc Length ~ Enter the minimum length of an Arc segment. Arcs less than this length will be converted to line segments. The length of an Arc should be less than the length of a few 'steps' as defined by your CNC machine. The software cannot interpolate an arc if the arc is only a few steps long.
Min Arc Radius~ Enter the minimum radius of an Arc segment. Arcs less with a radius less than this value will be converted to line segments.
Tangential Deviation~ Enter the minimum deviance that adjoining linear segments can have. Linear segments that are less than this value are joined into one linear segment. This value can reduce the size of the Machine Code file.
All values are Lengths.
2. I have no idea....try it?
3. with this command ticked any arcs in your .dxf file will be turned into line segments, the value sets how long each segment is, the lower the value, the smoother the "arc" will be. I have had to do this on 1 file, but did it in turbocad by exploding the arc many times, turning it into line segments.
Have you tried installing the latest version of software, or updated the firmware in your controller yet?
Have you tried swapping the x and y motor cables at the drivers to determine if your steps/mm problem exists in the software or hardware?
What difference in steps/mm do you have to make to get the machine to cut exact?