PCB alignment base for milling

Milling a double sided circuit board is quite challenge without a proper setup. The copper layer on the clad laminated sheet is very thin, to mill this layer evenly, we need the surface of the copper sheet to be parallel to the movement of the Z-axis. The tool used for isolating the copper traces also needed to have very fine tip (usually 0.1mm or 0.2mm). For double sided circuit, it's even more challenging. After mill the first side and flip over to the second side, the CNC machine will need to an exact reference (0 and 0 on X and Y axis). To make this process easier, I design a setup (base or fixture) that have a to surface is milled with a flat end mill to make it parallel to the Z axis movement, and 2 edge that are parallel to the X and Y axis. With this 3 reference, you can precisly mill a double sided circuit. please take a look at the video for instructions.