Hi I am in the process of learning milling in 3d on the school's 3 axis axyz cnc machine.

The model and tool path are generated in Rhino and imported to tool path.
Q: In toolpath output, what do I input for DEPTH ?

I have tried setting it as 0, 1 , etc. When I run it, the machine runs the tool path about the stock.

Please help me ! Greatly Appreciated !

In CAM, output the proper code. That is, have it go to the proper depth of cut as if you were really cutting metal. On the machine, edit the work coordinates (where you set up your XYZ on the part) and bump the Z wear offset up enough so that your deepest cut is up above the metal.

1st you need to know where the Z offset of your tool is set. I am assuming you or someone set the tools up when installing them in the machine, if not run away, because I guarantee you are going to crash the machine.

In CAM software you position your stock relative to it's position to Z zero in the real world. Now you can set your depth of cut and have it work.

EG if your cutter offset (on the machine) is set to zero on the table. and your part to be cut is an a vise - lets say the top of the part is 5" above the table.
If you have tool 5 in the spindle - then to position the tool exactly on the top of the part your code should be G0 G90 H5 Z5.0(H5 tells the control to use the height offset for T5(this may be what you are overlooking in RhinoCAM BTW)).
So to cut .5" deep in this part your Z height in the actual code will be 4.5".

It will take another 2 pages to explain the CAM setup, so you can check this stuff 1st and repost.