I am attempting my first pcb with a cnc router. I have everything in orderbexcept for compensating for uneveness with gcode ripper. I designed assuming the board is 2mm smaller than the actual dimensions to give 2mm tollerance either side. Thisbworks great but now looking at the gcode the bit is moved to y-0.6? Why doesnt it start probing at x0 y0 because its now barely on the pcb?