This thing is so nimble in the air yet has a fraction of the complexity of a regular helicopter. I wonder if this method will scale up to "full size"?
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.
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.
With full sized helis, it takes a long time to spin up the rotors to speed before the pitch is changed to take off.
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.
It's a great solution for reducing mechanical complexity in mini/micro sized UAVs, though.
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.
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.
With a regenerative approach, you'd probably need very little net electric power.
http://www.smithsonianmag.com/videos/category/history/the-se...
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".
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...