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Yaw gotta be kidding me, it won't stay on the heading I tell it to.

Discussion in 'Phantom FC40 Help' started by IflyinWY, Jun 11, 2015.

  1. IflyinWY

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    Sometimes when I yaw, like for a panoramic video, or just trying to yaw 10 or 20 degrees, my Phantom acts like a stubborn dog that doesn't want to turn it's head. Then all of a sudden BAM it yaws too fast.

    I input yaw control, and sometimes it yaws, and sometimes it doesn't. Sometimes it yaws fast and sometimes it yaws slow.

    I've used the cardboard with a hole cut out to ensure "constant and steady" input, but it still yaws slow and fast.

    FYI: It also has one heck of a time making it's mind up about where it wants to hover. One second it's fine where it is, and then it wanders over there and might even change altitude. Oh yea, then it'll wander somewhere else.

    I'm as confused as my bird. Here's a short video from today. I did not yaw left after about 4 seconds into the video, while it's still fading in.

     
    dirkclod likes this.
  2. RoyVa

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    Have you done the IMU calibrations.
    IMU( Inertial Measurement Unit = Accelerometer + gyroscope + compass)
    Roll, Pitch and Yaw. Without almost any drift.
    The IMU is an electronic sensor device that measures the velocity, orentation and gravational forces of the Quadcopter.
    These measurements allow controlling electronics to calculate the required changes in the motor speeds.
    It's a combination of 3 axis accelerometer and a 3 axis gyroscope and a 3 axis magnetometer (compass) for better Yaw control.
    The accelerometer measures acceleration and also force and measured the downward gravity force. As it has 3 axis it can work out the orentation of the quad.
    The gyroscope measures angular velocity, in other words rotational speed around the 3 Axis.
    A magnetometer measures the direction and strength of the earths magnetic field. The sensor can then determine which way is north and south. The pole locations are then used as a reference with the Yaw angular velocity around the gyroscope to calculate a stable Yaw angle.
     
  3. IflyinWY

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    Thanks RoyVa,
    Yep done numerous Basic and Advanced IMU calibrations within the past month.
    Also "Reset the Compass" using a magnet.

    I even repositioned my compass yesterday, moved it down on the stock landing gear, just about 1/4 inch. I got to thinking maybe I put it too high and it wasn't mounted plumb. There was no improvement. The video was shot after moving the compass.

    How high is a factory installed compass mounted when the bird is sitting on a smooth level surface?

    I'm pretty familiar with the functions of both IMU and Compass, but something is escaping me. :confused:
     
  4. RoyVa

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    With what I see in the video I would double check my RC's stick calibration and operation. Hook up to the assistant and slowly move the sticks (yaw control) and verify that it is responding. move it through several girations to verify it is not a bad stick or its sticking. You should be able to see it responding and running smooth. At least this will eliminate the problem being here.
     
  5. IflyinWY

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    Sounds good, I've always checked each stick and switch when plugged in to NAZA, except yesterday... :rolleyes:
     
  6. IflyinWY

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    The sticks were calibrated perfectly without making any changes. Any other ideas?
     
  7. IflyinWY

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    I have a new compass on the way... :confused:
     
  8. RoyVa

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    From what you are describing really sound like the yaw control,stick is hanging up, or sticking then making contact so the quad jumps. Only way I would know to trouble shoot would be to try another controller and see if it stops, if not problem in the quads circuits.
     
  9. IflyinWY

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    I don't think anyone else in Wyoming has a Phantom... :(

    Cleaning the contacts wouldn't be a bad idea, if it's possible. I'm sure they could use it considering where I fly. How silly would it be to open it up and hit it with compressed air? Our compressors don't blow much water vapor. :)
     
  10. RoyVa

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    Compressed air would only clear any loose debri, contact cleaner would breakup and help remove any electrical corrosion or film. If you can't get that the next best thing would be to use denatured alcohol and move the stick around to help during cleaning. Let it dry real good before powering it up. A good way to check tthe stick would be to plug it in the assistant and in the calibration tab move the stick around and watch it's action on screen and see if you can see any delayed action or jumping around. If it does then may be time to try cleaning or even replacing. Might be able to find a controller on eBay that you could salvage from or even use. I pick and extra for $40 one time. Depends on the type of controller.