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Stopping motors in the air

Discussion in 'Inspire 1 Discussion' started by RaptorMan, Dec 23, 2015.

  1. RaptorMan

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    It's my understanding that if you're flying your drone and you pull both stick down and to the inside the motors will stop and the drone will drop to the ground -- is that correct? I can see this method to shut of the motors after the drone has landed, but doing this in the air could spell disaster. And I can think of a situation where you might just want to move the sticks that way in the air --doing a rapid spiral descent!

    So, can someone confirm this is a thing and if there's a way to prevent this from happening?


    Brian
     
  2. John Alan

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    It will shut them off midair...
    Suggest you never fly maneuvers that come close to doing so...
     
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  3. msinger

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    Get this:
    CSC Safety - Phantom Help
     
  4. ringolong

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    Will it shut them off on full throttle down when it is in the air?

    I know the csc will, but I am wondering because a full throttle down is how I stop the props once it is on the ground, and I am afraid to test this while descending. I usually descend at 3mph, but I notice when testing the RTH it was dropping much quicker o_O
     
  5. RaptorMan

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    I asked because although I'm still waiting to get my first drone I've been reading up and looking at videos to acquaint myself and I guess the idea that a maneuver like that could cause the drone to drop from the sky and possibly fall on someone or some thing just doesn't seem reasonable.. What's the logic behind this in the first place?

    In war zones the pilots are often told to do a rapid descending spiral to land instead of the normal approach as it reduces the opportunity for bad guys to shoot at the plane. So clearly, a rapid downward spiral isn't an unheard of move in the real world.


    Brian
     
  6. World Media

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    It will indeed result in the unintentional stopping of the rotors turning your inspire into a rapidly descending, out of control BRICK hurtling towards the ground ready to injure anything it hits. God forbid it is close to high enough to reach anything close to terminal velocity!

    DJI can prevent us from using full power effectively if its a little cold ....... but allows us to shut off the machine unintentionally while airborne. Way to Go DJI!
     
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  7. RaptorMan

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    One last question on this ... how long does the sticks have to be in the CSC position before the motors are shut off?

    OK, one more question ... if you happen to do this can you restart the motors before it hits the ground if you have enough time to try? That is, once the motors are off are you prevented from trying to restart? I'd think that simply advancing the left stick should do the trick.


    Brian
     
  8. Blue Bird

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    1.5 seconds.:cool: And No, None have recovered from a full shut down after that.
     
    #8 Blue Bird, Dec 23, 2015
    Last edited: Dec 23, 2015
  9. Tj_

    Tj_

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    In the flight simulator I have to be 250ft or higher, then I can perform a CSC and recover. Any lower results in a crash. So if it was to happen in real life you'd have to react lightning fast! Or crash. I've never timed it, but it takes just over 2 seconds to perform a CSC.

    Simply advancing the throttle doesn't restart the motors. It has to be the CSC maneuver.

    This feature is there for a reason. If your drone is accidentally falling towards a group of people, please kill the motors. A heavy object hitting someone is bad enough. Adding spinning props is even worse!

    If a bird happens to snatch your drone (it's happened), please kill the motors. Don't chop up the poor animal so it suffers and slowly dies.

    But this feature should be activated a different way. A separate switch under an emergency flip cover should be setup to kill the motors. Primary flight controls should never be abel to kill power while flying!

    Please be careful. Practice on the simulator. It's available on the iPhone, PC, and just recently added to android devices.
     
    Blue Bird likes this.
  10. RaptorMan

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    Thanks man, good post and explanation. It does make sense that we should have a way to kill the props, but it should be a dedicated switch and NOT the primary flight controls.


    Brian
     
  11. World Media

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    There is little point in shutting down the rotors in all but the very rarest of cases. If the rotors are still turning the drone is not in free-fall there is a degree of retardation to the descent and you always have the possibility to recover. If you crash and hit something with the rotors running they stop themselves WAY faster than the three seconds it takes for you to shut them down, they may spin quickly but they don't have enough power to have inertia and significantly damage anything ( even Julio Iglesias's fingers when he decided it was a good idea to grab a motor while it was mid flight!).

    Its a subject that many disagree on here ..... in my opinion it will become a law suit at some point in the future in the USA. Fingers crossed it never happens to any of us!
     
  12. Blue Bird

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    Absolutely, The simulator is close but can lag compared to actual flight and response, not the same. It's very important to get this info out to the newbies though! It's a 6Lb Monster for god sake. Let's get them up to speed!
     
    #12 Blue Bird, Dec 24, 2015
    Last edited: Dec 24, 2015
  13. Tj_

    Tj_

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    Newbies need to read the owners manual. It clearly states with an exclamation mark
    "Do not perform CSC when aircraft is in midair, otherwise the motors will be stopped."
     
  14. Blue Bird

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    Gee, I remember when i crashed my FC40! Sticks down and in means that it is the end. LOL!
     
  15. FlyHighUSA

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    I am an authorized dealer and I have actually been sharing emails with DJI lately addressing this very issue. I was descending rapidly due to a battery failure issue when in mid flight the motors shut off when the throttle was about 1/8" away from the bottom of the throw that is available on the throttle stick. A CSC command is a great idea for arming the motors but according to my experience lately when lowering the throttle stick only to a low position resulted in a disarm of the motors. I have several Inspire pro and phantoms etc. and I will be checking this on my other drones. I have constructed a catch net made from a fish sane to catch my drone . So basically I am going to hover above the net then lower the throttle stick and see where the cutoff is. Have any of my fellow flyers out there had an issue with the throttle stick in the lower position cutting power to the motors???.I would have thought you would need to lower it to the full bottom of the throw to disarm the motors. I don't recommend doing this to anyone. This is not an accepted maneuver and could result in a damaged drone. Hopefully this is a isolated problem with my machine, I would love to hear what you guys think. Thanks in advance for the help.
     
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  16. Blue Bird

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    Try re calibrating your RC.
     
  17. Tj_

    Tj_

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    I'm paranoid when it comes to long descents. I'll pulse the controls on the way down instead of holding down. Supposingly holding down on the controls while flying won't kill the motors. I believe the vps needs to see or sonically hear the ground to enable this feature. The simulator verifies this. But I'm not testing it myself. I'll just keep to my paranoid pulsing.
     
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  18. FlyHighUSA

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    Yes I thought the same thing and did just that but the same issue resides, not only that it is in more than one. I'm waiting on DJI Tech to get back with me. Thanks for the idea though, I do appreciate it.
     
  19. FlyHighUSA

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    Yeah that is a good idea, but this particular time I had a tb48 battery go from 85 % to 10% within 2 seconds, bad thing is it was a perfect performing battery up to that point. I do like you and normally pulse or just come down slow but this was an extenuating circumstance. Scary as heck with a 4,500 dollar rig lol. I got very lucky.Merry Christmas
     
  20. Kilrah

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    And you don't make the obvious connection between "battery failure" and "motors stopping"?
    Your motors didn't shut off because of your stick position, they did because the battery had failed...
     
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