I’ve modified previous gcode sketch putting “cutout” before “drill” but there’s the same issue. It’s NOT caused by gcode or MPCNC, I’m pretty sure that the fault is in the tool. When it is all inside the hole an impredictable vibration can trigger a flutter that ruins the work. I think to buy a more accurate spindle and better tools.
Do you think that a 400W chinese spindle (in the photo) is better than my old manual economic 400W spindle? It’s advisable to change Universal Mount with a dedicated, more rigid mount?