Z offset in which software?
If everything is calibrated correctly, you may not need any Z-offsets to compensate for a mis-calibrated Z.
In Slic3r, you could set a "Z-offset" of -3 to compensate for a machine which thinks Z=0 when the hotend is 3mm above the bed. (See [
manual.slic3r.org]) Then the generated Z-code will start referenced from Z=-3mm and hopefully print on the bed.
Edited 1 time(s). Last edit at 04/10/2014 11:35AM by DaveX.