I imagine it could work like Android 9-patch PNG drawables, which have an extra ring of pixels around the perimeter that mark content zones and stretching zones.
Electric motors remove a lot of the complexity in powered-lift flying machines. As soon as your power/endurance requirements demand a combustion engine, you also have to manage the complexity of a piston engine or turbine (jet) engine.
This means either including a crankshaft and optionally a system of gears to route the rotational power along the axes you want the rotation in, or ducting the output of a jet turbine in some way that drives the rotors. In addition, there are different limitations with regards to the time required for a given change in RPM as compared to an electrical motor.
My impression is that a lot of the complexity in conventional helicopters (and flying machines in general) stems from the limitations of combustion engines. There's a reason that you very rarely see vectored thrust in conventional airplanes, for example.
Of course, if batteries and electric motors become sufficiently powerful, this changes the dynamic and it will become possible to design electric aircraft that re-evaluate the traditional design restrictions. This is one of the reasons that the rapid progress of electric cars is so exciting.
I don't think a hybrid like what you suggest is practical.
Locomotives need lots and lots of torque at zero and low speeds. This would otherwise necessitate a huge transmission. Plus, the weight penalty for a train locomotive isn't nearly as severe as it is for any kind of flying craft.
Other commenters have mentioned a hybrid system, with a relatively small electric motor that generates just the instantaneous torque changes needed for the control system, but the majority of the power is supplied via direct mechanical linkage as in today's helicopters. That might be viable, but I'm not sure. The weight and complexity penalty for the old control scheme isn't so bad when scaled up, but is really bad when scaled down.
So a hybrid scheme (like in a Prius) might be practical, by my estimation.
Probably not, for the same reason that a quadcopter doesn't really scale to full size. The inertia effects of larger rotors make changing the speed of the rotors within a rotation much harder.
With full sized helis, it takes a long time to spin up the rotors to speed before the pitch is changed to take off.
Well the critical difference here is that changing blade speed is not needed or desired. They just need to change blade torque, which would apparently immediately cause a change in blade pitch.
I don't see a specific reason why this wouldn't scale. I do wonder what changes in load do to the system though. If it can't handle changing loads without messing up the blade dynamics, it would only work for fixed payload systems like camera platforms.
You can use an electric motor. We can easily make extremely high power electric motors (see: CNC machines and Diesel trains), and power storage will continue to improve.
The added cost of batteries at even today's prices could be worth it for the decreased mechanical complexity of the rest.
If all we need to do is change the torque of an electric motor, that can be done essentially instantaneously even at high power levels.
Power storage may continue to improve, but it will take a long time before you hit the energy density of fossil fuels; the difference between batteries and fossil fuels is something like a factor of 10 (actually greater than that, but electric motors are more efficient so let's say 10 for the sake of argument), and it's improving much more slowly than Moore's Law, doubling maybe once every 10 years. That means if those trends continue (and there's no guarantee they will), you're looking at 30-40 years before the energy density allows electric helicopters to be competitive with fossil fuel powered.
For cars, energy density isn't quite as important, as the weight of the car is not the dominant factor in its efficiency (it does have an effect, but the aerodynamics, engine efficiency, transmission efficiency, tires, etc. all make a big difference too). But for a helicopter, every pound you add to the batteries is another pound you have to lift, so energy density of your power source is quite important.
So, if trends hold on battery technologies, it will come about eventually; but I would put money more on the decades timeline than the years timeline.
I don't think scaling this up is a question of inertia it is more a question of weither a material exists that can be used in those flexural joints with much higher loads.
This is a material science question. A material may exist that has the right combination of flex, strength and lets also not forget durability. I am a mechanical engineer and crack propagation and cycle fatigue would be a major concern for a joint like that at large loads. There are all kinds of amazing tricks material scientists know how to play to combat these types of problem.
I think this could be scaled up if material to make those flexure joints exist.
You could couple a high power combustion motor with a relatively low power electric motor via a differential, and have the electric motor do the 'high frequency' modulation the combustion motor is incapable of.
With a regenerative approach, you'd probably need very little net electric power.
Sure it would work. It only needs a variable clutch on a standard engine and the motion on the blades is very slight and mostly balanced, so the torque difference should be pretty manageable.
Depending on what you mean by scaling up. There have been single man vertical take off and landing (VTOL) vehicles that have two rotors and require no variable pitch for directional control so they are even simpler then the system in this video since the 1950's! The first such vehicle was the Hiller VZ-1, dubbed the "Flying Platform". If you are in the bay area you can go check a real one out at the Hiller Aviation museum next to the san carlos airbort (30 minutes south of sf). Or enjoy watching this video...
Directional control is achieved by leaning, the gyroscopic forces from the dual rotating blades creates inherent stability without any feedback system. They are like segways of the sky. Reports say it only took 20 minutes for a non pilot to learn how to fly it. These machines are incrdible and I don't understand why more hasn't been done with them.
A late 1970's version called the williams x jet WASP added a cruise missle turbojet for more horsepower, and was coined the "flying pulpit".
As an aside I think a vehicle like this could be developed today and fall under the FAA ultralight powered vehicle classification (weighing less then 254 pounds and carrying less then 5 gallons of fuel). This classification doesn't require you to have a pilots license!
People here might also be interested in the Mosquito Air helicopter as well. It falls into this ultralight classification and is a kit you can build in 200-300 hours. It costs about $30,000...
Big rotor = big moment of inertia = more energy lost on accelerating it and slowing it down each time. At some point it's better to rotate it at constant velocity and change pitch independently.
That's what I was thinking. That would require electrical motor control of the blades. Maybe turbine generator for power source. I would imagine this kind of pulsing would cause severe fatigue on the parts if they scale up too large.
The parts will cycle back and forth exactly as much as they would in a traditional helicopter, and there are fewer comparatively small parts. It would likely be stronger and more fatigue resistant than current methods of controlling blade pitch. We can program the motor to change torque as smoothly as we want.
It would probably work but I'm guessing the overhead of the extra actuators is much smaller at full size, so this may not be as helpful as at small sizes.
The complexity of the conventional helicopter method is not only providing control, but also a considerable amount of safety by enabling autogyro capability. This lack of autogyro is already restricting the quadrocopter setup to "let it crash" dimensions and the same well be true for this admittedly very clever duocopter.
