Need Help!- gross positioning error tnc 2500 mill

[arsenalandy]

hi all recently i have been having problems ref z axis but put it down to bad weather placed a heater near the machine and its been ok
today it came up with z axis drive error , switched off back on and it cleared, then later on half way through the day just finished a cycle when it came up with "gross positioning error z " i had the electrical covers off and noticed on the third card along the was a red light on trf3 , switched power off again and it rereffed ok but soon came back with the gross error fault again any help would really be appreicated
thanks andy

[cncserveng]

Check the lubrication of the ballscrew and ways, seems to me to be a tight axis.

Check the axis % load on the axis servo page.

You may need to support the axis on a block and undo to ballscrew nut to get a feel for how tight is is.

[machintek]

You can change the display to LAG. This shows the deviation between the commanded position and actual position. If it exceeds a parameter, it displays this error. These motors have brushes. May be that they are worn out and cannot transfer enough juice to the armature. Or you may have a tight axis as said.

George