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Idle creep, unstable takeoff, losing altitude

Discussion in 'General Discussion' started by Joevano, Apr 27, 2015.

  1. Joevano

    Joined:
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    Location:
    Zimmerman Mn
    Some minor issues starting in my new Phantom. When touching down, if I just quickly click the throttle into idle and then let it back to center, the idle starts to creep up.

    When I take off, it wobles to one side instead of going straight up.

    Lastly, within maybe 3 feet of the ground, it does not hold altitude well, sinks.

    Are these all related to RC calibration?
     
  2. 4wd

    4wd

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    Location:
    North York Moors
    The throttle creeping up is normal, not sure why it happens but often reported on here once it 'thinks' it has taken off.
    When you are taking off it needs full throttle straight up to head height..
    It will sometimes tend to tilt toward the battery if you go at all gently.
    Different surfaces make this worse.

    I suspect the sinking when close to the ground is just an effect from being near the ground but not sure what it's called.
    Ground Effect maybe :rolleyes:
    Even so it's worth hooking it to a computer sooner or later and calibrating sticks then doing the Advanced IMU even if it says not needed. I always feel it flies more stable when I know it's done a good calibration recently.
     
  3. TeamYankee

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    I suspect throttle creep is due to barometric pressure, this may increase ever so slightly when flying under ground effect and the NAZA thinks it's descending slightly, so increases throttle.

    When landing.. ALWAYS hold the throttle lever down to power off or it can tip over as it wanders about under the randomness of GPS accuracy limits.
     
  4. donco234

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    Location:
    Oregon Coast
    wind, especially gusty wind conditions have slight barometric changes moving past the bird. I live near the beach and it is very windy most of the time. I have noticed that if I am in a hover and a gust hits the bird, it sinks 2-3 feet and then recovers. My theory is that the wave of pressure causes the barometric sensor to think that the bird is rising then falling and it tries to correct. Not sure.
     
  5. Hughie

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    Yes indeed. Whenever I do a hand catch in windy conditions, I always do a finger count afterwards:eek:
     
  6. peter west nz

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    Yup!
     
  7. Ti22

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    Location:
    San Diego
    Couple things I’ve “learned” about my Phantom 1 takeoff. I no longer use GPS mode for lift off - Atti only (of course good GPS lock and compass calibration).

    Also, I find slamming throttle up too quickly often tilts my bird. Too slow can be a problem too - a smooth, moderate up throttle is how I achieve level lift off every time. A weak, saggy battery will also tend to tilt the AC during lift off.

    Hovering a few feet off the ground I tend to use only Atti mode as well.