I'm new to 3d (and 2d) CAD. I'm interested in learning and how I'll learn is by inputting my Cozy plans (when I get them) into a CAD file. This will be for my own benefit (learning). I was following this thread and many CAD programs were mentioned and some technical jargon used to describe certain features which at this present time is foreign to me. So in simple terms the following is what I would want from a 3d CAD program. I'm assuming that sub-parts are created ie bulkheads and accordingly dimensioned (inches/cm). Other parts created, dimensioned. Then along the way connect all the sub-parts to eventually end up with a complete airframe. I'm also assuming that it's possible to work backwards in that a fuselage is created, then point and click to a spot for an automatically dimensioned bulkhead to be inserted only for some fine-tuning maybe (thickness comes to mind). From a completed file, I'm also assuming that if a change is required, say widen the cabin by 5" that all the other parts are accordingly re-sized to suit. Specify material type. Print out accurate 2d drawings of any given sub-part. Lastly, making the airframe into a solid, skin it, colour it etc. I'm thinking (hoping) that the above is standard 3d CAD stuff. As I mentioned I'm new to this and so I'm not sure whether my assumptions equate to basic, intermediate or top end CAD programs.