I'm seeing something new in my Taig CNC mill and want to verify the required actions. Using Mach3 and a 1/4 inch flat end mill, I find the edge of my stock and set the Y axis to -0.125. I jog over to the positive side of Y and do the same on the X axis. Then if I command the Y to move to -0.125, it's off slightly. Machs DRO reads -0.125 but after finding the edge again, the Y axis now reads -0.1261. After reseting I noticed the following:
If I move Y from -0.125 to -0.5 and use the command to move back to -0.125 it looks accurate, if I move Y from -0.125 to 0.5 and again move to Y-0.125, it's off by 0.0011. Furthermore, if I start Y at -0.125, move to 0.5, then move to -0.5 and return -0.125 in a continuous motion, it's accurate.
So basically once I move the Y table towards me, it doesn't move away from me for the first 0.0011 that the motor turns. This is not related to something I changed recently in the software or to the machine. Last week all three axis were accurate, last night, I bagan seeing the error in my finished parts and measured tonight to confirm. X and Z appear accurate. What adjustment would be nessesary to resolve this?
Thanks so much for any sugestions.