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Phantom 2 wobble

Discussion in 'Phantom 2 Discussion' started by J__F, Jun 28, 2014.

  1. J__F

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    Hi there

    today for the first time i had an intense wobble when hovering and flying in gps mode. (Phantom 2 with h3-3d and go pro black approx 4weeks old) before the flight i had adjusted the tilt speed on the gimbal from 50 down to 2. would making this adjustment affected the stability at all? should i do a overall calibration every time i make this adjustment?

    cheers
    John
     
  2. BMEWS

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    no. it wouldn't have any effect.

    can you provide more information on what you were doing prior to going into hover, and perhaps a more detailed description of the "intense wobble". What height were you, etc etc.

    bmews
     
  3. J__F

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    takeoff was from an open grass field flat average auckland overcast day slight breeze - started up motors as normal, gps had 9 sattelites as soon as it was off the ground instant wobble side to side - front to back. quickly bought it back down checked props, gimbal, controller etc nothing looked out of place. started back up again as soon as it left the ground the wobble was there, got up to approx 5m up trying to hover and it was still there? plugged it in to dji assist all settings at default (except tilt speed set at 2). just trying to think of any other possible causes - i recently got a EVA Shoulder/hard Case for carrying everything - everything fits quite snug with purpose cut eva foam for body, radio etc. could storing it in this case may have put pressure on the body/motors in some way? only other thing i did different was i had the go pro lens cap on when i powered up - i took it off after powering up the phantom
     
  4. BMEWS

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    thanks for the update.

    Couple of observations.

    Assuming you're in NZ. Are you aware of any flight issues such as J-Hooking and TBE (toilet bowl effect) that others with high declinations are reporting? It is a possibility that your "wobble" could be TBE. Think of water going down a sink plug (coriolis effect). But without some more detail (and having never experienced it myself) You'd have to do a little research and check out some videos to see if it's a similar issue.

    GoPro lens cap? I'm assuming the gimbal did a bit of freaking out after power up as the H3-3D is supposedly balanced for the weight of a naked GoPro. However, this shouldn't affect flight especially if removed before take off.

    What mode were you flying in (GPS, ATTI, Manual)?
    Did you have anything else attached to the airframe such as prop guards?
    Assuming you checked that the props spun onto and locked on the motors properly?
    Can you hear any difference in the motors (such as pulsing) when sitting at idle (props spinning) on the ground and when in the hover?
    What pre-flight checks did you do?
    Have you checked if any of the motors are stiffer? (without props OR power on) turning them by hand should give you some indication.
    Have you checked whether any of the motors have any vertical or lateral movement (not fully secured) including both the motor housing AND the individual spindles?
    Can you actually describe the wobble (better yet video it and stick it on YouTube). It's difficult to fathom out whether it's a flutter or you're getting some serious balance issues.

    The important questions are :-
    How long has this been going on for?
    What (if anything) changed between normal operation AND the induced wobble other than you changing the gimbal tilt speed?
    Did you do ANY other changes within the Phantom assistant? (such as gains)
    Can you provide some screenshots of your Phantom Assistant settings?
    What revision of Firmware are you running?

    Others i'm sure will start kicking into the conversation as the picture builds from the info you can provide.

    Cheers

    Bmews
     
  5. J__F

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    thanks bmews appreciate the reply - I have the noticed TBE and j hooking when flying since day one and I'm learning to adjust flying technique to compensate - I've been following the forums here re the beta testing. this wobble didn't seem to look like any of the tbe jhooking vids I've seen but good idea to try and get a vid up if it continues.

    always flying in gps mode i have not attempted atti or manual
    no prop guards - i have an fpv transmitter and mini iosd attached on belly behind the gimbal since day one with no issues
    after first wobble i double checked props were all on correctly and tight
    motors all look secure with no movement, all feel similar when turning by hand
    pre flight check i will power up phantom, let it warm up on ground, find satellites, check fpv and iosd info on screen, let it idle for 10-20 seconds or so then take off

    hopefully the weather this week will let me get out again and fly - i haven't had the chance to fly again since the wobble happened.

    its only happened the one time (both flights on the same day) - after i adjusted the tilt gain and I've started transporting it in a hard case with foam.

    running 3.04
     

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  6. EMCSQUAR

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    Could you post a pic of IMU calibration page - I'm curious to see #s. Try an advanced IMU calibration see if that helps cure the wobble.
     
  7. J__F

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    pic attached
     

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