Mori SL-80

[Sully01970]

Z axis is loosing home position, I can reset home but if the machine is turned off it will loose home. Any ideas?

[underthetire]

What control? If its a newer one with ABS pulse coders and battery backup, change the batteries first. If its an old one, 6t-10T, does it zero return to the switches correctly?

[Sully01970]

it's an msc-518i

[underthetire]

Ok, so 18iT control, probably D cell batteries in the elect cabinet door. Change those first to make sure they are good. How are you re-establishing home on it? Using the custom screen and setting zero point set to valid? I can't remember if the 80's still had zero return switches that late or not, I kinda don't think they did. I have seen the home position go away on the larger lathes if you just toggle the 1815 bit 4 and 5 parameter. Normally, bit 5 should always be a 1 , bit 4 goes to zero if home is lost. Bit 4 will go to a 1 if you use the custom page to re-zero automatically. All you need to do is turn on Zero point set to valid, jog the axis over till the arrows are about .1 from lining up, then press zero return, z+. Should move till the arrows pretty much line up, and 1815 bit 4 and 5 should be a 1.

[Sully01970]

I had to go thru that process last week when I changed out the Z Servo amplifier then again this morning when they started the machine after being down for the weekend. The battery was replaced just about a year ago. I don't think they are suppose to go out that quickly. Good thing we have spares.

[underthetire]

If it's the lithium batteries, ive had problems with those. They only have a shelf life for so long, so unless they get turned over from stock a lot, you can get a depleted one. And yes, they are supposed to be changed once a year. Switching over to the Fanuc battery box with D cell batteries is the way to go. I've done many of that conversion. Since you changed your amp, it is possible you got a bad one as well.