The expression “milling around”, as described by the Cambridge English Dictionary, means “to move around with no particular purpose or in no particular direction”. And so it’s a funny turn of events that what we call a CNC mill, does just the opposite. Tell it its purpose, give it its tools, feed it some material, and watch it precisely gnaw away with intent.

For this first test, I created two SVG files. One a large triangle, and the other a smaller triangle, so that when cut out you would have the outline of a triangle.

Here is the material with the cutout still inside of it.

Here is the larger triangle with the smaller triangle cut out, but still inside.

And here is the final result: