[HRWmfg]

Hello,
I have a Hardinge Cobra 42 with a 21T controller.
It's time to replace the control and servo backup batteries.
I've heard some say to do it with the power on. The manual says to turn the power off right before replacing the batts.
WHich is the best way?
Thanks
ken

[underthetire]

ALWAYS keep the power on. Just be careful not to touch high voltage. I know what the manual says, but changing them with the power off only works about 10% of the time, and only works if the old batteries are in good shape. I used to get a lot of service calls to re-zero turrets and axis even though the customer followed the manual.

[HRWmfg]

I wish I had got this sooner. The guy had already swapped the batteries with the machine off. It has a 300 set x and 300 set z zero error.
I've read plenty on this, but it is still confusing. The turret is in the U.0 W0. home position. What is the difference between the 1815 APC and APZ parameters? Which have to be toggled on and off and in what order?
Thanks,

[HRWmfg]

I think I've figured it out. Everything is back home again.