Hi Im Graham an Industrial Modelmaker of 25 years, my field of interest is 3D CNC machining and I use a Roland Camm3 and 'Toolchips' machining software, Toolchips is a Danish Cadcam program which originally I used in the early days of DOS and developed into Toolchips 'Quickmill' which uses STL format for machining, I must say I get truly awesome results from this and I now use it for making parts for my Model Aircraft Kits business.