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prop guards affecting calibration???

Discussion in 'Phantom 2 Vision + Discussion' started by Gorlo, Jul 7, 2014.

  1. Gorlo

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    Has anyone noticed a problem with calibration once prop guards were installed?
    It might be a coincidence, but since I installed the guards, I've taken the drone out twice and on both occasions, it went in circles until the third or fourth calibration attempt.
     
  2. Mori55

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    No , I don't see how this would affect calibration.
     
  3. Mako79

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    What country you in? Magnetic declination maybe? Going in circles is referred to as TBE (toilet bowl effect).
    Are you doing compass calibrations in open interference-free areas.
    Do you remove your phone and keys when you do the compass calibration?
    In regards to 2nd part of compass calibration, are you rotating on its nose and not cartwheeling it like most people do.
     
  4. Gorlo

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    I'm on Canada's East Coast, northeast of Maine, in New Brunswick.
    I did not experience this before I added the prop guards. It would be a strange coincidence.
    I calibrate before every flight, in areas free from EM interference; I don't have my cell with me, and I do the second part nose down.
     
  5. Mori55

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    So take the, off and try it. Make sure you put the small screws back in
     
  6. Gorlo

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    that's what I'm considering trying, to test. I'm just a little concerned changing screws again might strip the plastic.
     
  7. Mako79

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    Are you calibrating like below? Or in the second step, are you cartwheeling it?
    [​IMG]
     
  8. Channel70Productions

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    No problems here when using the guards.

    Remember to use the short screws if not installing the guards or bad things will happen.
     
  9. Meta4

    Meta4 Moderator
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    There's no need to be recalibrating every flight unless you are traveling a long way between flights.
    Once you have a good calibration just stick with it.
     
  10. Mako79

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    This is the scenario:
    You travel 20kms from the last "good" compass calibration point.
    At the new site, you don't notice that there is more interference (rebar, more high voltage, cell towers etc).
    You calibrate thinking it's required.
    You take off and she spirals and circles all over the joint.

    What do I suggest:
    Don't calibrate unless you have travelled a significant distance. eg >50kms, another state, another country or if you have sub woofers in your car.
    Get your satellites and take off and see if she goes TBE (toilet bowl effect). If she does, then calibrate. If no symptoms of TBE - have fun.
    Need to remember also that the DJI app will warn you if a compass calibration is needed.
    Another option would be to bring a laptop/windows pad and check the compass MOD (1300-1600) is within range.

    A few things I have noticed, If I take off on man made structures/concrete, the compass calibration required warning always appears. I pick her up and take off using my case/back pack/wooden table and the warning goes. What I think is that the compass is way too close to the ground where it is heavily affected by the geomagnetic forces and therefore the compass goes berserk. I will do some field trials, taking off at 5/6ft (hand take-off using an assistant - boat launch technique). I will then see if she TBE's at close locations.

    My phantom has been suffering from TBE from day1. This is due to the magnetic declination. Australia east coast is 10 degrees off true north.

    Remember, this is only a suggestion.
     
  11. Gorlo

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    I was just going over all my footage so far and I realize the TBE was occurring before I installed the prop guards. @ Mako79, that calibration diagram is exactly what I follow: step 2 is nose down and I circle the drone around me, or I circle around the drone (either way it can get dizzy after a few tries). I've started to only do calibration sporadically, when I notice 'stronger' TBE (which I define as: spiralling outwards in an expanding circle). I take off from grass or a picnic table. With or without calibration, when I leave the drone to hover (at the beginning or in the middle of a 12 minutes flight), it tends to circle around. It bugs me as I want to get in close for some stable shots.
     
  12. Mako79

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    what degrees are you on the magnetic declination map below?
    [​IMG]
     
  13. cougar

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    Location:
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    More then likely it is the magnetic declination (TBE) I have this all the time and after flying for a few minutes it settles down.
    Am located close to you so if you do not have this problem I would be very surprised.
    No need to calibrate all the time, just wait it out. A firmware fix (3.05) might be released next week.
    BTW. we are booth at -18 so that is how much the compass is off if you are in NB.
     
  14. Double-D

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    What part of the east coast are you?
    I'm near Byron Bay and never really had a problem.

    Edit: I do notice mine drifts a little after initial take off but settles down within 10 sec. From what I've read it seems all do this. Maybe I never hover long enough to see if it goes in circles. I'll try it tomorrow.
     
  15. cougar

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    Location:
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    OP say's east coast Canada, not Australia
     
  16. Double-D

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    Location:
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    I was asking Mako79
     
  17. Mako79

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    DD is actually referring to myself.
    I'm from Sydney.
    BTW DD, since our toilet flush differently to the northern hemisphere, ie our **** goes up instead of down, which way do you spin your phantom when calibrating?
     
  18. Double-D

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    Haha. I spin mine clockwise, but I like to sit on my hand and make it numb first so it feels like someone else ;)
     
  19. Gorlo

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    Yep, I'm in Bathurst, on the north-east of New-Brunswick. I've done an IMU calibration last week and it seems better. I've also noticed the TBE tends to settle down after a few minutes. Like a good apprentice, I was following advice to land and calibrate the drone as soon as I see this effect. Damned if you do, damned if you don't ;-)