When I’m working in mm, it seems like the minimum increment for a cut depth is .1mm. If I enter a number less than that it just rounds up to .1mm or down to 0mm.
However, if I switch to inches it will allow much smaller increments, down to .001". The toolpaths seem to render just fine this way, but I seem to remember reading that grbl doesn’t really like working in inches, and I’ve had issues in the past with it. Plus, I prefer to work in mm since that’s how the machine is marked and it just seems to allow for greater precision in other areas.
I’m cutting copper and have had mixed results with broken bits and missed areas, even after machine-flattening a buck screwed to the wasteboard. I know this is indicative of a non-flat work area. However I’m at the limits of what the tools in my workshop can accomplish in terms of tuning.
I figure that if I can use a smaller DOC, it will help account for the discrepancy in my work surface. In other words, if my material has a ±.05mm variance, and I’m trying to take a .1mm cut, it could hit areas that are .15mm and snap the bit. But if my DOC was .05mm to start with, it would only encounter a max .1mm thickness per layer and it should be fine.