My way was to export the part as a dxf file which could be read by ESTLCAM. It´s nice to build something in FreeCad but somehow you have to convert the single parts of your construction into a g-code. But now I want to start with something more complicated. Till now I only used librecad to create the panels (It´s quite hard to create a panel with text on FreeCad).
I have a small cnc to produce the parts I need for my build using linux cnc and ESTLCAM to create the g-code. The main reason I´m using FreeCad ist that´s a helpfull tool for my hobby: Constructing a flightsimulator. I´m experimenting with freecad now for one year, but though this fact I´m not a very experienced user.