Double sided circuit (PCB) - How to mill (etch) precisely?

Milling a double sided circuit is challenging in its own way. The copper laminated layer is very thin (~0.04mm) and the spacing in between the trace is very narrow.
To cut the copper evenly, the surface of the copper sheet needed to be parallel to the movement of the Z axis. And when milling a double sided circuit, the board needed to be flipped to mill the other side, this required a finding of a perfect reference (zeros on all 3 axis X, Y and Z). To make this process easier, I make a setup that will help you to do just that.
After the setup is prepared, I showed you the workflow of PCB milling using AutoDesk EagleCAD and FlatCAM. These 2 software are free (Eagle has some limitations on the free version).
The tool used must have a very fine tip (0.1mm or 0.2mm diameter) for isolating milling. Most the the tools that I tested broke very easily, almost right at the moment they touch the PCB. Till now, the only tool that work for me is a double edge V-bit. And I also used a 0.5mm end mill tool for drilling holes and cutout the board from the copper sheet.

Here's the link to the CAD model of the setup (base or fixture):


0.5mm end mill tool:


0.1mm V-bit:

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