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This “spherical flight vehicle,” reportedly a prototype for the Japan Self-Defense Forces, has a single rotor and is said to be capable of 40 mph flight. And as the video shows, it’s quite nimble. The catch? An 8-minute battery life. But the idea of enclosing the whole thing in a spherical frame so it can maneuver and land heedless of the orientation of the blades is pretty brilliant. More deets at wired.co.uk.

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.


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Comments

  1. Anonymous says:

    It’s a fake. Has to be.

    Nothing is ever blown around by the down draft. That thing would move her clothes around quite visibly.

    It also appears to be unrealistically stable.

    I don’t see anything to keep it from rotating from the single rotor. There would be something to counteract that, like the tail of a helicopter or a counter-rotating rotor. Even some sort of internal fins would work, but I don’t see them.

    I’d love to see something like this that’s real, tough.

    1. fuzzy says:

      if you look at the video her the downdraft is clearly moving her clothes at around 0:33, and from the article: “Inside the roll-cage you’ll find a propeller which is used for thrust, and eight separate
      wings for control.”

      1. Naimo says:

        Come on, Make, that’s clearly a fake video !

        1. it is very real and in fact a very simple design that has been around for years. here’s a video of an RC that works the same way just without the round roll cage (which is really the only new thing in this video).   http://www.youtube.com/watch?v=4aWyH6iswuQ

    2. johngineer says:

      It’s quite likely it’s real. For several reasons.

      1. The draft could be directed straight down like a turbine, to provide the maximum amount of lift. You do see the effect of the draft on her clothing at around 0’33″, but only when the unit is hovering above her head.

      2. The stability could be provided by a counter-rotating mass which is co-axial with the motor. This counter-mass is smaller in diameter but more dense, so it can provide an adequate counter-moment. A larger mass on the bottom would also serve to help the unit stay upright.

      3. The program on which this segment was originally aired — WBS (World Business Satellite) — is a popular and respected tech/business show in Japan. It’s unlikely that such a program would throw away their credibility by intentionally producing and airing a “fake” report.

      1. Anonymous says:

        I honestly hope it is real. It is very convincing, and very very cool.

        It just moves too smoothly, to me.

      2. Scott Harris says:

        Weight at the bottom will not make this type of vehicle stable. A spinning mass can not provide the torque required to counter the prop-torque.

        1. johngineer says:

          please explain.

          1. Scott Harris says:

            The prop-torque is countered in this vehicle by the control vanes in the sphere. You can see that they are tilted to generate counter torque in the prop wash. It’s true that satellites use reaction wheels to generate torques, but this requires a angular acceleration, not a constant angular rate in the wheels. Eventually, the reaction wheels will be going too fast and they will use a thruster burn to spin the wheels down. For the hovering sphere, the prop-torque is always there, so a ever increasing angular rate on a reaction wheel would be required.

            You can use a rotating mass to provide gyroscopic stability, but thats’s not what they are doing here. They are using active stabilization. You can see the vanes actuate to keep the craft stable.As far as the stability goes, it’s hard to explain, but the idea that being bottom heavy implies stability also implies that when the vehicle is not vertical there will be a restoring torque about the center of gravity. This is not how it works out. Consider the case where all of the mass is concentrated at a point somewhere below the rotor. The prop thrust vector goes through the center of gravity, so it can not provide a restoring torque and the mass distribution is destabilizing.  Draw a free-body diagram to see it. In addition, the bottom-heavy viewpoint ignores the dynamics and aerodynamics of the rotor and that’s a huge factor in rotorcraft stability. Consider an airplane or an rocket as a rough analogy. Make them nose heavy increases their stability.

          2. johngineer says:

            cool! thanks, Scott!

    3. johngineer says:

      It’s quite likely it’s real. For several reasons.

      1. The draft could be directed straight down like a turbine, to provide the maximum amount of lift. You do see the effect of the draft on her clothing at around 0’33″, but only when the unit is hovering above her head.

      2. The stability could be provided by a counter-rotating mass which is co-axial with the motor. This counter-mass is smaller in diameter but more dense, so it can provide an adequate counter-moment. A larger mass on the bottom would also serve to help the unit stay upright.

      3. The program on which this segment was originally aired — WBS (World Business Satellite) — is a popular and respected tech/business show in Japan. It’s unlikely that such a program would throw away their credibility by intentionally producing and airing a “fake” report.

    4. Capt.tagon says:

       Quad copters and Hexacopters are unrealistically stable. A good inertial system will do this.

    5. it is very real and in fact a very simple design that has been around for years. here’s a video of an RC that works the same way just without the round roll cage (which is really the only new thing in this video).   http://www.youtube.com/watch?v=4aWyH6iswuQ

  2. Jeff Bernstein says:

    Highway to the Danger Zone!!

  3. Jeff Bernstein says:

    Highway to the Danger Zone!!

  4. Mark says:

    Years ago, in some of his short stories, Larry Niven postulated “copseyes” .   Spherical hovering police-surveillance devices…..

  5. Anonymous says:

    All I can think is Dr. Who.

    HERE COME THE DRUMS!

  6. Capt.tagon says:

    Oh for pete’s sake, rotating masses to control torque spin, impossible because of torque spin, it’s a fake video because we’re too unimaginative to figure out how it works. Quit overthinking it with complexity or worse yet underthinking with a dismissive “it’s a fake”.

    Have none of you have been paying attention to vectored thrust applications in current aeronautics?
    It’s got an eight element gill fin mechanism down there if you know what you’re looking at which vectors the airflow. You can see them in operation in front of the tree at 0:57, at 1:20-1:29 where the guys hovering it next to her and one directly in front of it’s camera as it follows her up the stairs at 1:32.

    We also have real life helicopters that fly with a single rotor. You blow air through a rotating thimble valve to vector airflow out of the tail boom. NOTAR. No Tail Rotor, no contra-rotating rotors.

  7. “Stay low!  In eight minutes the sentinels will go back for recharge and then we can move again.”

  8. Anonymous says:

    Throw a ball of twine at it.  That’ll take it down and no need for fire power.

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