FreeCAD is really a effective three dimensional CAD modeler and drawing tool that is specific squarely in the mechanical engineering and product design fields. The program's .12 version number informs you it's not ready for prime time, but when you are interested in this region - especially if you are acquainted with Python scripting - plus there is already plenty to understand more about here.
If you have samples to hands then FreeCAD can already import DXF, OCA/ GCAD, SVG, STP/ STEP, IGS/ IGES along with other formats, a fast method of getting began and find out exactly what the program can perform.
But when you want you'll be able to also produce a new document on your own. FreeCAD supports 2D objects like lines, rectangles, arcs or circles, in addition to various three dimensional primitives (box, sphere, cylinder, cone, torus), because both versions may then be altered in a variety of ways (translation, rotation, reflecting, scaling, offset and much more).
You will find also lots of mesh tools a drawing module which exports forecasted sights of the geometry to some 2D SVG document along with a raytracing module which exports your projects for rendering in POV-Ray.
And Python code underlies all this. All you do inside the interface will problem some Python command, which you'll examine. You are able to freely enter Python instructions yourself should you prefer a a bit more versatility, or perhaps create macros by recording any particularly helpful Python for replay later.