cincinatti z axis servo fail

[rolson8302]

I have a Cincinatti arrow 750 with acramatic 2100. after tool change when spindle starts and Z starts to move, machine power kicks off and error message "z axis servo fail" comes up. Spindle continues to run until unit shut down, have to restart machine to cure problem. This is what the cause says, The Z axis following error has excedded the configured servo fail limit. Any Ideas ?????

[cncatj]

Hi Rolson,
Based on my own (Limited) experience with Cincinnatis
This problem could be caused by a stuck Z axis Motor brake , You can identifie the problem , Try to run only this machine , all else quiet ok , you will hear the motor
trying to run against the brake pads , so a extrange noise will be heard , ( If the problem is the brake )

[rolson8302]

There is no noise it grabs the next tool the spindle starts z axis just starts to drop and it cuts the machine power the spindle the spindle slowly winds down till it stops then you have to restart the machine.

[Pophamrt1]

Start by checking your line voltage. I had the same problem and it turned out to be one low leg of the three phase power. The Z Axis uses the most power so shows it first by stalling and then registering a "Servo Failure" message. I don't remember the exact figures, but the Sabres like a pretty high relative line voltage (at the high end of 230v). It's posted on the back of the machine. HTH.

[rolson8302]

Thanks for the reply thats the first thing I checked and I cant be sure The start up voltage does drop to about 225 from 239 for about a seconnd in the hottest part of the day.It have been ok running on rapid override witch will bee less voltage.The error allso says check comnnections and gain. How did you fix your voltage issue

[Al_The_Man]

A following error is due to the servo not being at the commanded position within a certain limit, set by parameter.
This can either be because the servo is unable to move fast enough due to friction, load etc or is being back fed by a force such as a Z axis counter balance failure,
If neither of these, then the encoder feedback is maybe missing, due to encoder or cable failure.
Al.

[rolson8302]

There was another error after the first error that says something like what you are saying.I thought it was because it tried to move then machine power was stopped so it would be out of alignment but when i restart it I would only have to realign the tool drum and not the axis What does this mean and how can it be corrected.