Before you start on this procedure you must have the following steps already completed, please read the instructions entirely before starting.
Pronterface installed and working on your computer,
You must be able to connect to your 3D printer and get successful output from the “M503” command.
You must have completed the paper level procedure on your 3D Printer to ensure that the Bed is level as compared to the X gantry
in this article, anything highlighted like this;
will have to be typed into the command line interface within pronterface.
G28 - this will home the 3D Printer
G29 - This will run an auto bed level for your 3D Printer
G1 X50 Y30 F1000 - This command will position the nozzle somewhere close to the front of the bed
G1 Z0 - Move nozzle to Z absolute Zero
M114 - This will verify the current position of the Z-Axis
G92 Z10 - This command tells the printer that the Z-axis is at Z=+10 without actually moving the nozzle
M114 - you can verify that the previous command was successful without actually moving the nozzle
M211 S0 Turn Off the Software Endstop
At this point, you can use the Pronterface interface to manually move the Z-Axis/nozzle down or up until a piece of paper just catches between the nozzle and the bed
Once you have the setting correct so the paper is just able to barely move follow the commands below to finish
M114 - You need to see what the 3D printer believes is the new Z Position In the video example below we got back a value of Z:8.5
Now its time for some math
10 - Current Z position + Thickness of paper = new Z offset
Set this new value with the M851 command. (ensure you set it as a negative number)
M851 Z-1.4 - Sets the new Z offset
M503 - Verifies the new value was accepted
M500 Saves the new values to EEPROM
M211 S1 Turn the Software Endstops back on
I have included below 2 links that may be useful as well as providing additional information.