Lu,
Funny you mention the sidewinder transmission as that is what I was thinking about calling the whole machine! I had envisioned something like an astar main gearbox and engine assembly turned sideways to the airframe and made to pivot around the input. Now since you have the engine off center in the airframe you move the cockpit/cabin area slightly off center the other way to balance the machine. this also opens up the area just in front of the mast such that when tilted forward we aren't chopping up the cockpit!
I was already expect the use of either fly by wire flight controls or even a hydraulic or teleflex cable type arrangement to overcome that situation.
As for the work being done on variable diameter rotor systems, is it a benefit to a normal helicopter layout or only to a tiltrotor type set up? It seems like a very complex solution to an already complex machine. At least my idea just moves things that aren't spinning at high speed!
Thanks for the discussions so far, it has been most interesting. Keep the replys coming!
MaxTork