[Einsteinli]

Hi,

I got myself a 3018 CNC to mill circuit boards or other small things.
This is my first point of contact with CNC milling, so please beginner-friendly answers ;D
Setup and commissioning went smoothly. I have calibrated the eSteps and when I move 10 mm in x, y or z I also measure exactly this with my caliper.

Now to the problem: If I want to mill a test groove created with Easel, it does not adhere to the parameters stored there, whereas GRBL does:
According to the .nc file (test1.zip), the groove should become 0.6 mm deep by 3 a 0.2 mm deep milling passes.
According to the included GRBL software (only that seems to work), the CNC mill also follows this exactly.
However, 0.6 mm is removed on the first pass (but according to GRBL, the spindle is only at z=-0.2 mm working coordinate). In the two subsequent passes, the mill removes nothing more, but the working coordinate in GRBL Candle does nicely what they should do.

I hope you have some good ideas

[joeavaerage]

Hi,
to make circuit boards, especially with features down to 0.2mm apart you need to machine to an exact depth with great accuracy. The copper of a standard board is 35um, (0.035mm).
The tool needs to go through the layer but CANNOT afford to go much further into the substrate. The problem is that the machine will not be perfectly flat and the PCB blank will have minor
warps and bows. If you cut to 50um (0.050mm) deep, then at some places it wont cut through the copper but at other places will be too deep.

I use Autoleveller, a software utility so I can probe the PCB blank, and measure any deviation from flat and Autoleveller alters the Gcode to keep the cut depth spot on. I've been using it for eight years,
and daily in the last several years. I could just not make good boards without Autoleveller.

Craig