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
I think this all just depends on the intent. As a camera platform it could be beautiful with nice, slow, graceful movements, no jerking around. I nice, consistent panning and zooming. Can't think of much else use for it. It would get quite boring after the second or third light.
Since the topic is big, here is a full size octo.
https://www.youtube.com/watch?v=_3yjpX54s_U
I CW for stbilize that kind of Quad you need to put flap above the ducted fans so you can govern the yaw. I doing a lot of test on a special huge quad and that is better solution
I've built a 36" tricopter using 65mm ducted fans, was able to lift and hover at 4ft, BUT no yaw stability and precision yaw control sent the thing spinning. The control laws are somewhat different from what I found (can't say due to job). And having servo-actuated vectoring is in the end a bad idea--too much weight and complexity for the thrust EDFs put out.
I do have a 1260APM laying around and 4 55mm ducted fans... nice recipe for another experiment here. :)
Another Example of Heavy lift developed using mp32 :
https://www.youtube.com/rnavoni#p/u/27/cXRwh7zsD8s
An other solution is to use 1 motor and variable pitch propeller
http://www.virtualrobotix.com/video/hg3-willy
... we yet fly last year in that configuration .... this year instead i develop a lot of heavy lift as
VR Dragon
http://www.virtualrobotix.com/profiles/blogs/foxteam-support-and-im...
best
Roberto
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...
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...
-
1
-
2
of 2 Next