maybe its the cold? (been about -8 °F here lately). my 4020 is having issues with the spindle and the coolant. maybe the keyboard on the control is getting sticky? two days ago I had gone out to buy something and left the spindle running to warm up, 3500 RPM, facemill tool in the spindle - no program running or anything, but the spindle on at that speed. when I came back the coolant had come on, and the doors were open - so you add it up: spindle on at 3500 rpm, 3" facemill in the spindle, doors open, coolant on. It took me 2 hours to clean up the shop and the coolant turned on again at random while I was cleaning (doors closed).
that same night I was running a part and after the roughing pass the machine switched tools for finishing, came down and the spindle didn't turn on. even though it was a finish pass - 0.015" is enough to snap a $75 relieved shank 3/8" endmill.
Now this morning, I am warming up the spindle (doors closed!) and the coolant came on again. In addition to that, the spindle shut itself off earlier this morning while I left it running to warm it up.
Any ideas about these issues? at first I thought maybe the 1 in a million chance happened that the serial noise had commanded the machine to turn on the coolant. Since it's happened again, there's no way. either its a stuck button, a stuck relay, or my control is taking a dive.
Similar question with the spindle though. why would the spindle randomly turn off? will it randomly turn on I wonder? say during a tool change? or when I am doing something inside the machine? this is bad news stuff! if it's a stuck button, the spindle won't turn on since you have to hit 'shift + spindle on/off'.
maybe I should disconnect my keyboard to see if the faults still occur? anyone had these issues before? I have a cnc88