AC Servo Driver problems cause sizes unstable

1-      The signals lost causes the driver lost steps.

Solution: Can be checked by reading the pulse number on the AC servo driver, or use the Dialgage to check if there is any signal lost.

2-      AC servo driver buffering parameters are not proper.

Solution: Adjust the buffering parameters.

3-      The feedback cables of AC servo motors are broken, or the socket, jack are wet which causes the signal lost.

(From http://www.CNCmakers.com)

Solution: Change the feedback cables of the AC servo motors, and improve the protection.