From Hack-a-day. This ducted-fan beast uses the Sparkfun 6DoF IMU that Jordi wrote the software for. No, it hasn't flown yet.
Behold the Land-Bear-Shark, a quadcopter on a rather grand scale. At a full eight kilograms it’s an easy target to compare the [Howard Hughes] behemoth, but in addition to the weight, this still has yet to make its first flight.
To give you some scale to the image above, the board at the center is an Arduino. It controls the beast, along with the help of a SparkFun IMU board which rides atop. Really, if any quadcopter of this size has a chance of working, this should be the one. The construction is beautiful, making use of carbon fiber rod along with 3D-printed connectors to assemble the frame. A lot of thought has gone into small things like conserving weight used on the landing gear, which are incorporated into the bottom corner brackets. The batteries are connected in a manner that makes them easy to adjust, acting as ballast for balancing the craft.
Comments
old shit with bad efficencty and much noise, bad control stability.
impellers are not a good choice for a hover platform
the Levitake.de Copter is more then 3years old
here has some one tried to make some tests with the chassis from levitake, but its not good
http://forum.mikrokopter.de/topic-21754.html
If the control surface impacts the airflow in this T (supposing top is closed and bottom open), this is how it impact a sort of turbulence, where the airflow can fill the T, more or less.
As the open T side is rigidly oriented downward, the influence of the control surface could be limited, except if proper dimensioning of the whole system is adequate.
There is a lot of MAV example where a ducted fan/shroud propeller features vectoring vanes, on 2 axis, and this is a proven design.
As far the Huge Quadrotor is concerned, I understand that the servo at each fan is to counter the rotation generated by 4 CW fans.
After this "neutralization", I understand the attitude stabilization and governing is the same as used in our quad kopter.
A last remark is to notice the huge powerplant needed (LiPo characteristics) to get enough thrust from these ducted fan, based on high speed airflow, where tubing the airflow is just a first step to take advantage of aerodynamics. This is high voltage, high amps project not guaranteeing a manageable and satisfactory thrust to weight ratio.
My ongoing Propeller Shrouded Project (already 2 shrouds builds for test bench experiment is aimed at maximizing the propeller/multiblade custom rotor thrust by aerodynamics to get more thrust, or to reduce the needed power.
I have no particular belief, I just build custom shroud, stator, rotor based on different studies, and I just measure the outcome by experiment, to conclude if it is worthing shrouding, or not, applied to RC scale dimensions (Reynolds number impact).
My upcoming tri-shrouded, and quad-shrouded is perhaps at the opposite of this huge thing, consideirng the aim of reducing the powerplant.
When I say large blades, I mean blades that serve the same purpose as an airship. So these blimp-blades would be covered with photovoltaic film, would make the variable-pitch quad rotor extremely light, and make it possible to cruise high altitudes practically and indefinitely. The blades could charge the vehicle's electronics and power the onboard electronics. A quad-rotor airship...
How quickly can the control surfaces be changed? Back in the atomic age, people thought they would get rocket packs and fly around. Now that the general population is more mature in aerodynamics, we can see the value of larger control surfaces and little power. Devices like the Gen H-4 are a more likely substitution to realize our predecessors' dreams.
IF someone wanted to SUCCESSFULLY build a ducted fan design, the key is to keep the speed of the ducted fan constant, and use a plenum with a control surface to direct the flow of air.
Similarly, I don't know why someone hasn't figured out to make a variable pitch quad rotor with huge blades that require little power. You could even use solar panel film on hydrogen filled blades themseves to power the aircraft, and use magnetic bearings to eliminate friction at extremely high altitudes. To be continued...
Which model is the ducted fan?
Found used components:
HK 120mm EDF +Turnigy T600 Brushless + Turnigy Sentilon 100A + Nanotech 5Ah 10S
That was one of the first designs I thought would work. Boy, was I ever wrong! Seems there is this brillant guy who sank his entire life into making a quad-ducted fan vehicle into a reality. It never worked, but at least he got to see part of his dreams realized. A nice article about the Moller SkyCar can be seen here
Okay, back to the Variable Pitch Quad Rotor...
http://www.etotheipiplusone.net/?p=1470
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