The sacrificial wood base, bolted to the mill bed in the step above, will almost certainly not be flat with respect to the toolhead of the mill.

How does one actually go about creating an isolation milled circuit board There does not seem to be a lot of documenatation on the Internet of the actual steps involved.

The discussion below uses the various GCode types produced by the Line Grinder software (along with a CNC mill) to create a nicely aligned double sided isolation milled PCB.

Note that this is just one methodology that seems to do a pretty good job.

It is entirely possible that there are other, perhaps better, ways.

The example below shows the milling operations performed on the GCode generated from the TestPattern.gbr suite of Gerber files.

You are dealing with machinery which has tremendous power and can move objects at tremendous speeds.

There are many, many, things which can cause a bit to break, or a board to come loose, and these will shoot about the room as a painful projectile.

Pcb Milling Software Free Of Charge

Note also that the Line Grinder is offered free of charge, as-is, and there is no warranty or guarantee as to the accuracy of its output.

Pcb Milling Software Code Is Fit

You, and only you, are the sole judge of whether the code is fit to run.

Use the Line Grinder software to interpret the Gerber and Excellon output of your PCB design software and produce GCode files from it.

This process is discussed in the Line Grinder help files and is not discussed here.

You will need the following files: Bed Flattening GCode, Reference Pin GCode, Isolation GCode from the bottom copper layer, Isolation GCode from the Top Copper Layer, Edge Milling GCode, and Drilling GCode.

For example, if the board is single sided you will not need the Top Copper Isolation GCode.

If the blank PCB is already the size you wish it to be, then you will not need the Edge Milling GCode.

The steps below assume a double sided PCB will be isolation routed, drilled and cut from a larger blank PCB.

The image below shows the Line Grinder software displaying the Isolation GCode which will be executed in step 6.

Note the PCB is shown at about 3x magnification in the image below.

Several steps (Reference Pins, Drilling and Edge Milling) will plunge the bit through the surface of the PCB.

You will almost certainly not want the bit to be cutting holes in the bed of your mill.

Thus a sacrificial piece of wood is used and the blank PCB is mounted onto that.

A scrap piece of MDF or similar thick, dense particle board does the job nicely.

Also, be aware of the thickness of the board and make sure the settings in the File Managers that generate the GCode are such that the generated GCode does not plunge the bit completely through the wood.

The image below shows the board being mounted on the mill bed.