If you mean CAD, I found that FreeCAD works nicely as a parametric 3D modeler with some nice macros and addons, with the perk of also running on Linux
E: added info
If you mean CAD, I found that FreeCAD works nicely as a parametric 3D modeler with some nice macros and addons, with the perk of also running on Linux
E: added info
I'd agree that blender is very good. I find that it would be more suited to static stuff and renderings, as well as animations. FreeCAD is more like the commercial CAD software you'd find (Fusion 360, Solidworks).
On the topic of blender, It has some amazing features, and I am amazed at what people do with it (I also find it a bit tricky, but I probably just need to put a few more hours into learning)