Shameless update from Dale Kramer

On Sunday, March 20, 2016 at 7:41:42 AM UTC-4, Andy Blackburn wrote:
Dale - It's a pretty clever design. Thanks for sharing - gutsy move. ......

Thanks!

I am sure that a rotor disk loading of 18 lbs/ft^2 and thrust efficiency of about 5 lbs/hp is well within any theoretically feasible region for rotor design. At least it better be. I am basing my hover ability on motors and propellers that already exist. In fact on our Joby JM1 motors with 36x20 props at 4400 rpm we are getting about 110 lbs of static thrust at about 14 kw input to the motor controllers. That is about 5.9 lbs thrust/input hp (not motor shaft power!). This setup propels the eLazair in level flight at over 60 mph (the eLazair is pretty high drag at these speeds).
So, with about 500 lbs of static thrust from a WOT Rotax and 660 lbs from WOT electrics, the thrust to weight will be about 1.3/1. The electrics should only need about 1/2 power for hover.
The unknown is what amount of a zoom pullup versus a slow pullup and rotation thru a deep stall will be required. Rather than speculate on that I am just going to test it with model and full scale testing.
The transition is a very complex mixing of aerodynamic lift, aerodynamic drag, aerodynamic moments, thrust, thrust moments, mass and moments of inertia (probably other things too . I am sure I could spend a lot of time trying to model that mathematically but I choose not to at this point.

I think the broomstick analogy is not real good one for visualization because in my case the correction needed to bring the object into balance is not a sideways movement of the hand but simply an application of thrust moment about the center of gravity. During transition, the WOT signal sent to the multirotor controller should automatically result in WOT on the lower tail motors and 0 throttle on the upper tail motors and likely 1/2 power on the wing motors. Also there is still the elevator pitching moment that can be increased by design (at the risk of making high speed horizontal flight twitchy unless I use a separate, thrust vectoring horizontal plane or fly by trim tabs in high speed which I choose not to do right now). 3D RC modeling has shown what large area, high deflection surfaces can do. To start out I use the KISS principle and add from there.

Yes the electric nacelle 'tilt' method of countering the Rotax torque is expected to work for gross torque cancelling and the 'fine' adjustments will still be from the multirotor control of the electric motor counter rotations.

I am hoping to be able to handle at least one electric motor failure and possibly 2, depending on which 2. Model testing will determine this.