C'mon, you know you have all done it! I am spending the next three days (and nights) filling a customer order of detailed steel things, I am moving from a 9/16" end mill to a 1/4" to a 1/8" to a 1/16" to get it all picked up. The program has been working out each time I have done these in the past, soooooooo, after installing the 1/8" end mill I hit cycle start, adjusted the coolant line and went in the house to have some stuffed bell peppers a friend of mine cooked last night.

After I ate them I then heard the CNC shut down (it was time for the 1/16" end mill), I went out and saw that there was nothing done on the part, and then saw that the end mill was broke off !

Then there it was staring at me in the face, Mach 3 was still set to LOW spindle speed from the 9/16" end mill. I opened the door and the belt was still in low speed too............

The lure of the bell peppers clouded good judgement and a 1/8" 4 flute Atrax was harmed in the process. But since they are double ended I turned it over, zeroed the Z, changed the belt and used the "run from here" thing in the "comp run" screen and all seems well now.