Auto leveling is key to precise PCB milling. I wrote some open-source software that makes it possible to do auto-leveling on a CNC USB Controller-based machine like my chinese 3020 CNC. This software controls the actual control software so that it starts probing a circuit board in a grid-like manner, after which it can compensate for any misalignment and curvature in the GCode.| Giliam de Carpentier
Discusses the limitations of my 3020 CNC machine as well as some of the ways to work around them, allowing me to successfully mill things like LEGO-compatible bricks and circuit boards.| Giliam de Carpentier