Originally Posted by
blinkenlight
Stupid question: is your tool certainly intact? Because the thing 0.1mm v-tips love to do is snap a bit of the tip off and instantly become, say, 0.25-0.30mm v-tips, without this ever becoming particularly obvious unless one inspects the tip and/or compares it with a brand new tool under a magnifier. A related question is how do you hold down your PCB, and where/how do you set your height zero? Is it possible that whatever would be 0.07mm deep wherever you originally set it is actually a lot deeper where you do the milling? Because there is no such thing as a "flat" mill table when PCB milling is involved...