Uncontrolled Yaw

Discussion in 'Electronics' started by Anthony Shorten, Apr 13, 2014.

  1. Anthony Shorten

    Anthony Shorten New Member

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    Hi All,
    Hopefully some body can shed some light on an issue that I have had over the last year. On three occasions I have lost right yaw for about a period of about 6 seconds which is very unnerving as you can imagine. What happens is after yawing left then right then left I completely loose right yaw, I can give it full right yaw but nothing happens, I originally thought that this might be a motor issue but i recently replaced all motors with the new mk3644/24 and a brand new double Quadro cool board and on a flight on friday experienced the same issue. Could it be a faulty gyro on the flight controller board ? there are no errors in the log and I can see the sticks on the remote issue the yaw command and nothing happens ?? all motors are vertical and straight and my props are new.

    Any thoughts
    Cheers
    Anthony
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Anthony can you provide more details of the copter -- is this a Cinestar?
    What are the avionics boards that you are using, please? (Other than the double Quadro, which you do mention.)
    Do you have a GPX file from the flight where you had this problem? (EDIT) And can you post the file, please.

    Thanks
    And.
     
  3. Anthony Shorten

    Anthony Shorten New Member

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    Hi Andy, It is a Cinestar 8, FC2.2 Navi 2 firmware 2.04 the strange thin is that in the logs before the motor and distro board upgrade the opposite motors draw more power, and the same now that i have replaced motors, props and distro board. Cinestar is balanced perfectly as well.

    Thanks in advance

     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Anthony: Could you post the GPX for the flight where you had the issue please? From what you're describing, given that the Cinestar, the motors, and the props are all balanced, it's hard to account for the problem...

    Andy.
     
  5. Jason Smoker

    Jason Smoker Active Member

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    Andy Im thinking its a compass issue!
     
  6. Anthony Shorten

    Anthony Shorten New Member

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    Hi Andy,

    Here is the log.

    Anthony
     

    Attached Files:

  7. Anthony Shorten

    Anthony Shorten New Member

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    Hi Jason,

    I have had this issue once without the navi board connected, so my thought is that it could only be the FC ?

    Anthony
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Anthony: There is serious asymmetry in the motor currents. All the even numbered motors are drawing about half the current of the odd numbered propellers, those are the ones spinning clockwise.

    What is not clear whether this is an instrumentation fault -- or the data is really reflecting reality. I would suggest that you use MK_GPXTOOL and have a look at some of the earlier flights you did to see whether this is a trait that is reflected in all the flights.

    I'm not sure what the cause of the problem could be though. Usually one sees one "lazy" motor, but in this case all clockwise ones? Hmmm.

    Can you verify in MK Tool:
    1. Which parameter set you are using.
    2. Which mixer you have set.

    Thanks
    Andy.


    MK Version: FC HW:2.2 SW:2.04a + NC HW:2.0 SW:2.04a

    Flight date: 4/10/2014 4:38:17 PM
    Flight time: 4:38:17 PM - 4:38:45 PM (28 secs, 00:00:28)
    Batt. time : 29 secs, 00:00:29

    Start Lat./Lon. : -26.8260463 / 151.8968046
    Elevation(GPS) : 0 2.15 3.94 m (min/avg/max)
    Altitude(Barom.): -0.75 1.5 3.8 m
    Vertical speed : -1.07 -0.03 0.92 m/s
    Max speed : 19.1 km/h
    Max target dist.: 0 m
    Max distance/LOS: 16.6 m / 16.6 m

    Sats : 8 9 10

    Voltage : min. 14.4, max. 15.5 V
    Current : 0.5 42 71.5 A
    Wattage : 8 636 1029.6 W
    Capacity: 367 mAh

    Motor1: 0.0 9.7 15.0 A Temp: 24 26 28 °C
    Motor2: 0.0 2.2 6.1 A Temp: 24 24 26 °C
    Motor3: 0.0 9.2 13.3 A Temp: 28 30 32 °C
    Motor4: 0.0 2.0 6.0 A Temp: 24 25 26 °C
    Motor5: 0.0 8.3 13.1 A Temp: 25 27 30 °C
    Motor6: 0.0 1.3 5.1 A Temp: 22 21 22 °C
    Motor7: 0.0 6.3 10.0 A Temp: 27 29 31 °C
    Motor8: 0.0 1.9 5.4 A Temp: 22 21 24 °C

    Magnet Field: 104 108 119 % (ok)
    Magnet Inclination: 53 55 61 deg


    No errors found ;)

    Anthony Shorten Motor Currents 2014-04-13.png
     
  9. Anthony Shorten

    Anthony Shorten New Member

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    Okto 2 mixer set, same issues in earlier logs
     
  10. Anthony Shorten

    Anthony Shorten New Member

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    ohhh maybe the wrong mixer set, should i be using the okto mixer setup.......
     
  11. Jason Smoker

    Jason Smoker Active Member

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  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I think the correct one is the Okto2.

    Andy.
     
  13. Anthony Shorten

    Anthony Shorten New Member

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    on the okto 2 every second arm was shorter i switched the mixer settings back to okto maybe this will help.... any other ideas
     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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  15. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Anthony: I think you're taking the diagram too literally -- the "arms" are not shorter -- it's not a scale diagram. :)

    Andy.
     
  16. Anthony Shorten

    Anthony Shorten New Member

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    Sorry I'm plucking at straws here :)

    Anthony
     
  17. Anthony Shorten

    Anthony Shorten New Member

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    Hi Andy,

    What do you think, is this a Compass issue or maybe a faulty gyro on the distro board ? Its really starting to get to me

    Regards
    Anthony
     
  18. Gary Haynes

    Gary Haynes Administrator
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    We need a photo of your copter setup please.
     
  19. Anthony Shorten

    Anthony Shorten New Member

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    Hi Gary,
    Do you know anything about the Okto2b mixer settings on the new software, Sending a pic through soon.

    Anthony
     
  20. Anthony Shorten

    Anthony Shorten New Member

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    Hope this helps fc is out at the moment and 3 axis mount is off

    Anthony
     

    Attached Files:

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