I have always enjoyed 3D printing visualizations of math functions and realized that I can mill them with my MPCNC. These photos are the function cos(X^2+Y^2) . I used this simple openSCAD script http://www.thingiverse.com/thing:1052097 to generate the STL. You can download openSCAD from http://www.openscad.org/ . You will need to mess around with the function, scaling and ranges to get something that looks good. Next I used Meshmixer to reduce the number of polygons to a reasonable 9000 or so. Then I used Fusion 360 to scale the model to fit in a scrap piece of 3/4" pine trim. Finally I generated three tool paths in Fusion 360 CAM: 2D contour with holding tabs, 3D Adaptive clearing for roughing and 3D parallel for finish. I included some photos of the result and will follow up with screenshots of the tool paths from Fusion 360. Note that all these tools are free. For Fusion 360 you need to register as a student or a maker who makes less than $100K/year with the software.
The actual result is amazingly smooth, the closeup photos seem to exaggerate the mill marks. Note that some of the odd stretch marks are not from the milling but are in the model because of my mistakes in scaling and subsequently doing of poor job of undoing it.