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P3: What if one motor goes out?

Discussion in 'Pro/Adv Discussion' started by IceFireSoul, Jun 26, 2015.

  1. IceFireSoul

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    Does anyone know the answer? Technically, it CAN land "kind of" safely on 2 motors. Is this programmed, or will it just fly in the direction of the stalled motor full throttle?
     
  2. robsquad

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  3. IceFireSoul

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    You know it; or you are saying it because it sounds epic? I know hexas are programmed to fly with 5/4 motors in an emergency, for example.
     
  4. sergekouper

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    with 4 motors there is no way in this X configuration to stay in the air if one goes dead. Hexas can loose 1, 2 I don't think so.
     
  5. robsquad

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    i know it and the vid from the camera IS epic
     
  6. happydays

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    Go to the end.
     
  7. Altanore

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    It will certainly drop to the ground quickly. However, extremely unlikely a motor would just drop dead. You would notice it failing gradually.

    Sent from my SM-T700 using Tapatalk
     
  8. N017RW

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    Aside from physical or foreign object damage motors can't fail alone.
    Bearings are the only wearing parts.

    Typically the ESC is what fails and can fail in a mode which is damaging to the motor as well.

    This failure is usually a very brief incident with no warning.
     
  9. happydays

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    Same thing if a prop flies off. That's what happened to me in the video above. Same end result, though...
     
  10. Morgon

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    I will always wish that DJI would institute the 3-motor spin algorithm:

     
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  11. IceFireSoul

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    Normally a quadcopter can stay in the air and descend in a semi-controlled manner while spinning very quickly around itself, using just two opposite motors. If it's not programmed on DJI side, it's DJI's fail.
     
  12. robert velez

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    That quadcopter dropping in the river/sea is epic!

    I do hope DJI has some failsafe process if 1 motor does fail for everyone's safety.
     
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  13. N017RW

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    You just saw it in the video! :)
     
  14. rmfa

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    They don't currently. If you lose a motor or prop it hits the earth like a rock falling from the sky.
     
  15. Meta4

    Meta4 Moderator
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    Normally?
    No .. normally a quadcopter losing a motor is like a plane losing a wing.
    What you are talking about isn't a simple matter of smart programming.
    No manufacturer is making quads that can fly on 3 motors.
    The one in the video was a specially made research project.

    The good news is that losing a motor in flight is so rare that it's not really a worry.
     
  16. Jaybee

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    Research projects like that are what gave us these machines in the first place. As it's an algorithm, what reason is there that DJI couldn't implement a similar failsafe at some point? In other words, it is smart programming.
     
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  17. Meta4

    Meta4 Moderator
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    Yes .. it's smart programming - on a machine made specially to use it.
    If it was that simple lots of manufacturers would offer it but so far none do.
     
  18. Jaybee

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    No one said it was simple ; ) The point is, it can be done. There doesn't appear to be anything special with that test quad either, it's just a small airframe, flight controller, and 4 motors. No idea on their background, etc. but my bet is those guys will license that out at some point, if not open source it.

    Interesting stuff though, will have a dig into it a bit more.
     
  19. F6Rider

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    HA! there are enough people out there having a tough time flying on 4 motors, three would be impossible. Losing one motor throws the quad into an elongated flip, rotating around a point between the bad motor and the central hub, while flipping. You don't recover from that, you just watch in horror as it dives into the ground. Watch the video above in slo-motion and try to think of a way to recover it. (good luck) A VERY good reason not to overtighten the props and strip one.
     
  20. Jaybee

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    Look again, he clearly controls it and lands it safely at 0:40:
     
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