Leveling problems with Autoleveller and Mach3

[alvaroevc5]

Hello everyone.

To begin with, I am using a JFT 6040 CNC machine with a 2.2kW spindle, a probe, a 0.2mm - 20* - 1/8 inch shank pyramid endmill (also known as a square bit), mach3 software, windows 8.1 operating system, KiCAD for PCB design, and FlatCAM software.

So, I have been struggling with autoleveller for more than two days now. Even though I have a PCB well clamped to the sacrificial board (with screws, just tight enough to avoid deviations on the sides and corners), and even though I have repeated the leveling procedure multiple times even with different autoleveller versions (including two step leveling), I cannot manage to get a decent milled board, or at least not after the first attempt, which frustrates me even more.

The board is fairly small, and even so, in the first attempt, the whole thing was flawless, then, not even a single one is near OK.

I have adjusted since then the cutting depth on FlatCAM and reused the RPF for consistency (until moving to a different part of the PCB is necessary), and the tip of the endmill just floats over the board, enough to gently mark it, but nowhere near enough to isolate the traces. If I adjust the cutting depth too low, it goes too low and removes the traces, or sometimes it goes higher on some parts and lower on others, which is not supposed to happen after autoleveling I suppose.

Surface finish on the flawless one is great, whereas on the other tests, surface finish is rough, as if it where cutting too deep for some reason.

These are some pictures (Couldn't get to upload them here because file size is too large):

https://imgur.com/a/ZvSZZkI


Any ideas on how to improve or fix this to get good results?

Thanks beforehand.