I am looking for free CAD software that will produce Gcode or something that can be be converted to g code. I am using Mach for my 4 axis milling machine. I would also like to do some engraving
4 axis? I can't help you with a free 3D CAD program to make your parts, however I can with 2D.
For 2D DXFs, you can read the discussion and link to download here: Draftsight LINK
You can get a fully-functional demo of Cambam, and after 40 sessions you can create g-code that is limited to 500 lines: Cambam LINK