Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Toilet Bowl Effect (TBE) on a Phantom 1

Discussion in 'Phantom 1 Discussion' started by mikeve, May 15, 2014.

  1. mikeve

    Joined:
    Apr 17, 2014
    Messages:
    116
    Likes Received:
    6
    Location:
    Merrickville, ON Canada
    Hi Gang

    I've got a Phantom v1.1.1 with firmware 4.02. When it was new out of the box, it hovered perfectly. Now, after 20-30 flights, I'm getting a pronounced swirl at hover.

    Done advanced IMU calibration and compass calibration. Mod values 1,600 - 1,700.

    Live near Ottawa with declination 13w.

    It can't be the compass position as it was fine when new.

    Any thoughts?

    Thanks
     
  2. EMCSQUAR

    Joined:
    Sep 5, 2013
    Messages:
    1,692
    Likes Received:
    6
    Location:
    N 44.895 W 93.354 Minnesota
    Do a "Restore Default settings" from the IMU cal page, then advanced IMU cal, then stick cal then do your compass cal. Might check also to make sure your props are balanced.
     
  3. mikeve

    Joined:
    Apr 17, 2014
    Messages:
    116
    Likes Received:
    6
    Location:
    Merrickville, ON Canada
    Thanks Emcsquar

    Weather tomorrow is forecast to be crappy but I' try and let you know.
     
  4. ericdes

    Joined:
    Feb 12, 2014
    Messages:
    282
    Likes Received:
    0
    I live near Ottawa and I already wrote a topic on this subject.

    Turn your compass on the leg about 15 degrees COUNTER clockwise on the leg. It will hold on just fine.

    Do a compass claibration. Lift it, and it will be steady has a rock.
     
  5. mikeve

    Joined:
    Apr 17, 2014
    Messages:
    116
    Likes Received:
    6
    Location:
    Merrickville, ON Canada
    Ericdes

    Many thanks for your suggestion. I have read many, many posts on this issue and most of them also say to rotate the compass module. However, most of these posts relate to the P2 and DJI have admitted to a bug on that bird. DJI have also said that rotating the compass module is not, repeat not, the way to fix it (http://www.phantompilots.com/viewtopic.php?f=19&t=10317).

    If the P1 was subject to this problem, then my bird would have shown it right out of the box. Mine did not - it was fine at first.

    I have reset the IMU to factory defaults and, as soon as the weather clears, I'll see if that had any effect.

    Cheers
     
  6. ericdes

    Joined:
    Feb 12, 2014
    Messages:
    282
    Likes Received:
    0
    Actually this fix does not work on the phantom 2 because it's custom firmware should automatically compensate for the declination and does not. It's a bug. There is a rather long and technical post about this and pilots here are working with dji to fix it.

    This in fact work very well on the phantom 1. Dji themselves writes in the NAZA manual but the one they are talking incorporates the GPS and compass in the same module. We only need to rotate the compass.

    Trust me on this one it works and takes 5 minutes working 4 screws. Try it. Don't like it put it back the way it was.

    But you won't!
     
  7. mikeve

    Joined:
    Apr 17, 2014
    Messages:
    116
    Likes Received:
    6
    Location:
    Merrickville, ON Canada
    OK.

    I reset the factory defaults for the IMU, recalibrated the transmitter and the swirlies are gone!

    Many thanks Emcsquar.

    However, there is a mild bit of hooking after going straight out in CL. I'll try rotating the compass and check.

    Thanks to both of you.
     
  8. EMCSQUAR

    Joined:
    Sep 5, 2013
    Messages:
    1,692
    Likes Received:
    6
    Location:
    N 44.895 W 93.354 Minnesota
    You mentioned you calibrated transmitter, did you do advanced IMU calibration after restting defaults? If not make sure to do so.