I have a Series I Ridgid Ram Boss 5. I noticed today that when I program to cut a pass .100" deep I get a pass .105" deep. I started to mess with my backlash compensation, after adding .100" of compensation my cut was still .105" deep. I can see the compensation working because when the z axis starts to move the movement is extremely slow at first and then it will run at it's normal speed. I'm not too sure where to start to look for trouble. I removed the quill cover and out came about half an ounce of oil. I assume this is normal? I have replaced the x and y motors, but I'm still running the old Boss 5 stepper motor. I do have a spare that I can put on if this might be the culprit. Any thoughts?