Denford Software & Machines

hi
my micromill 2000ns will sometimes go to ref in z some times not, even though it may have been to ref position, it may then lose where it is. and instead of moving up to ref it will only move downwards. i have re installed the program, replaced the micro switch, but the problem still persists. any ideas??. many thanks in anticipation. baz

Have you tried greasing the Z axis screw/nut?

hi martin
lead screw greased, gib strip/free play checked, forgot to mention that the z movement can be affected whilst running a 'part' program, example, command to z10.0 after completing a cutting cycle the axis may move greater than z10.0 or less than z10.0, thus cocking up the next z position command. baz

Sounds like something is loose somewhere.
There is a fair bit of info here:
viewtopic.php?f=36&t=1419