I'm running a CNC router (Pacer 4010). I have been noticing lately that my tool height has been increasing and decreasing in height as I'm running a program. I thought my waste board was uneven but when I go to tool tip my bit, I'll be getting a lower or higher measurement than when I first measured it in the start of running my sheet. I'm not sure what would cause this. I thought maybe my bit is slipping a little bit inside the collet but I checked that and it was nice and tight. Could the cone be slipping down a little bit in the spindle? Has anyone heard of this and would happen to know the possible cause?
I didn't find the right solution from the Internet.