Note:
Use the software at your own risk. Author is not responsible for any damages.

Start cncjs to open the workspace

Connect cncjs to the cnc.

Connect the probes

Connect the positive of the probe to the Engraving Bit.
Connect the negative of the probe to the PCB copper surface.

Set the coordinate system

We will set the origin of the coordinate system to the a point that is a bit inside
of the bottom left corner of the PCB, so that it can be safely reached by the engraving bit when probing.

Move the engraving bit to a point above and inside, but close to the bottom left corner of the PCB.

In the Axes widget:
Zero out the X-axis and the Y-Axis of the work position

Now lower the Z-axis so that it is a few millimeters above the PCB.

Open the Probe widget:
Set the Touch Plate Thickness to Zero.

Click on "Probe" to start setting the zero of the Z-axis.

After probing is done, the Z-axis will be set to zero at the surface of the PCB at the starting point of the probing grid.

Open the AutoLevel widget

Click on Manage Widgets

Scroll until you find the AutoLevel Widget and enable it

The workspace will now show the AutoLevel widget

Setup the AutoLevel grid

Click on "Setup" in the AutoLevel widget to setup the AutoLevel grid

and define the probing area inside the confines of the PCB.

Choose the probing area to match the size of the area of the PCB that will be isolation milled,
but make sure that the probing area is within the physical PCB,
otherwise a crash may occur.

Example: red area

You can choose to save the g-code for probing to a file for later re-use
by clicking on "Make File"

or you can load the g-code directly into the workspace
by clicking on "Upload G-Code" in the AutoLevel widget

Start the Probing Process

Click on the play button in the Visualization panel.

The probing code will now start.
The results will be displayed in the AutoLevel widget table,
as the probe touches each individual point

You can apply the probing results to a G-Code file, or you can save the results for later.
This can be useful when you have the G-Code for the traces and the G-Code for the drill holes in separate files.

Applying AutoLevel results

We can now modify the G-code of the circuit.

Click on "Apply" in the AutoLevel widget

To use the results of the just completed probing run, leave the checkbox named "Use current probing data" checked.

To use the results of a previously completed probing run, check "Use a file" and select a probing results file.

In the section named "Original G-Code", click on the "Select" button and choose the file to which you want the AutoLevel results applied.

You can now upload the autolevelled G-Code to the workspace
by clicking on "Upload G_Code"

Or you can save the autolevelled G-Code to a File
by clicking on "Make File".

Remove the probe and run the autolevelled gcode

Example: Hello World

In this example, we will modify the G-Code of a text engraving by bending it to a curved surface

The probing grid is the same size as the Engraving

This is the engraving of the "Hello World" text after applying AutoLevel.