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Advanced Phantom goes crazy after manual/RC assisted take off

Discussion in 'Phantom 3 Help' started by wieshka, Jul 18, 2015.

  1. wieshka

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    Latvia
    Hey,

    I was taking off from roof of car as usual, spinning up manually, allowing 3-5 sec to spin a bit, and then by adding throttle. After 2-3 meters up above the car roof, P3 went crazy by starting to fly to the left away from me, multiple tries to stabilise P3 failed & it was like 170 m from takeoff position away continuing to randomly drift away.

    What I tried:
    - tried to push it with sticks to opposite direction as it is drifting, slowed down the drift only;
    - tried to switch to A mode, made it even worse;

    Luckily, I managed to push it away from approaching forest/trees and pushed in direction of wheat field, where, pushing as low as possible (eye sight) and then executing CSC (usually I dont read manuals at all, but I did for this purchase) to land as safe as possible, but might be that it was too late for CSC. Anyway, at least wheat field.

    Then the other part - finding the drone. Luckily connection to remote/pilot app was still good, distance 170m, into the wheat field. Visually impossible to locate, but GPS saved me from loosing my drone. Drone was in the exact position as shown on map via Pilot app and as well it was making noises because of trying to adjust gimbal.

    Now at home, I extracted .DAT, unfortunately, Phantom was not set to record mode yet. Now at home, did everything came in mind to check drones health:
    - spinning up motors without props - feels/sounds normal;
    - moving gimbal;
    - adjusting drone position with hand, gimbal adjusts as well;
    - no issues shown on Pilot app;
    - extracted .DAT files;
    - cleaned body - was with some wheat and bit with moisture from wheat field;
    - checked whole body against cracks etc, looks like that just original stickers are scratched;


    As my flight time is below 4 hours and I am very recent Phantom owner, please, tell me:
    - is there I did something wrong when it comes to pre-flight checks what caused drone to act so ?
    - is there something better to do in such situations in order to restore control or land it at least at some managed manner?
    - is there anything else I should do before trying take-off in order to understand - is my drone still in good condition ?


    P.S. unfortunately I did not try Return to Home, would it help as drone was not capable to maintain position in air, and I would risk to bump into that forest;
     
  2. C0ps

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    Never take off from the roof of your car. Metal effects your compass and calibration. You should of taken off from grass and calibrate away from any metals before take off
     
  3. Rogue Leader

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    Also, never install and power up a battery from the hood. Even though I launched from 20 feet away, the same occured to me.
     
  4. wieshka

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    So that take off from car roof/hood is the thing I did wrong.

    + good news - I did my spin off / take off with propellers just to test that everything is fine still, and looks like, it is.

    Looks like my first crash resulted in few very small scratches.


    Thanks guys.
     
  5. ScottyT

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    Yeah, sounds like metal at the take-off point interfering with its initialisation somehow. Experienced that for the first time myself when trying to take off from a concrete pier - lots of compass errors from the app, and even when I moved to a spot that didn't pop up an error, I was getting crazy drift after takeoff.

    Not sure why it continues even after you are in the air, or well away from the metal - there's obviously some reason.

    Check your IMU mod values are sane after you place the P3 on any take-off surface. If they are too far out, move your takeoff point.
     
  6. bobmyers

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    You need to do IMU calibration, gimbal calibration and of course a compass calibration at the field before you get ready to fly. Those should flush out any remaining demons.
     
  7. TheBabaBooey

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    What are acceptable IMU mod values?
     
  8. wieshka

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    This video - - and any other googling with keywords of your questions will deliver a lot of answers.
     
  9. kyba274

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    Dont do an IMU calibration at the field. Do one at home on a very level surface and don't do another IMU calibration until you crash again. Only calibrate the compass when you move a fair distance from home.

    The first compass calibration should be in a clear area with no metal around. A big park is ideal, given there are no underground wires.

    Never take off from or within a few meters of any ferrous objects. I take off from a plastic crate, which has so far put enough distance between the quad and any metal rebar in the concrete underneath to give stable compass readings.

    Good to hear your phantom is still in working order! Lucky save there.
     
  10. wieshka

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    Yes, for now I follow the rules:
    - IMU calibration I did just once after crash, at home, on very level surface;
    - recalibration I will do whenever there will be new safe firmware available, currently running latest;
    - compass calibration I do only when I do fly in area 50 km away from previous flying;
    - I do quickly check sensor readings before each take off;