SPCR

Looking at getting some designing software to construct virtual models, mostly of different types of windmills before trying to build them in the real world (part of school project). I've found two programs, Blender and AutoCAD and was wondering what would be better for this purpose?

I am not familiar with Blender, but AutoCAD is not a very good modeler. I would use SketchUp (which has a free version) or a solid modeler like SpaceClaim.