Here at Heeks Software, you can buy HeeksCNC 1.4, a CAD/CAM application for Windows, for only £10, that can help you produce the NC code for your milling machine. Many happy customers are already using HeeksCNC to boost their productivity.
HeeksCNC is totally open source ( see here for source code details ) . You can modify it to suit your company's needs. The NC code can be configured by editing files written in the popular "Python", a clear and powerful programming language.
Import solid models from STEP and IGES files.
Import DXF drawings; lines, arcs, ellipses, splines and polylines are supported.
Some limited 2D drawing functions
Create new primitive solids, or make solids by extruding a sketch or by making a lofted solid between sketches.
Modify solids using blending, or boolean operations.
Save IGES, STEP and STL.
Create drilling, profile, pocket operations
Post process to g-code
g-code is backplot to show red and green lines in the graphics window
configure your post processor for any machine with the editable script files ( see help for more details )
solid simulation of material removal