When adjusting the home offset (most often the Z offset) of a 3D printer using the M206 command, many users wonder which sign to use. In other words, in order to move the nozzle 0.1mm closer to the bed, do you use M206Z0.1 or M206Z-0.1. However, there’s a simple rule:
To move the nozzle closer to the bed, use positive coordinates, e.g. M206Z0.1 to move the nozzle 0.1mm closer to the print bed.
To move the nozzle further away from the bed, use negative coordinates, e.g. M206Z-0.2 to move the nozzle 0.2mm further away from the print bed.