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MK Gyro calibration question

Discussion in 'Cinestar Misc' started by Dave King, Apr 7, 2013.

  1. Dave King

    Dave King Well-Known Member

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    I thought I read some where on this board that if you recalibrate the compass or if you did a certain sequence with the joysticks that it can reset the Gyro calibration. When I refer to gyro calibration I mean the part that you set to make sure the flight control board is level and then go upper right with the left stick.

    The reason why I ask is that I noticed that when I calibrated my gyro's my machine was dead level. However after this last flight session I noticed that my #3 BL temps were sky rocketing. When I brought it home I suspended my copter and rechecked the balance everything was good. I double checked the motor alignment, the balance of the prop the whole 9 yards. Then I hooked up MK tools via the Xbee and I hit the 3D button while the copter was powered up but not on obviously. The 3D illustration of the copter showed that that the copter was indeed not level between booms 3 and 7. So I releveled the flight controller, recalibrated the gyro and rechecked the balance suspended and sure enough the 3D copter was dead on level.

    So I was wondering how my gyro calibration could have gotten so far off. I was thinking that some how the gyros got reset on location when the copter was not level. I could have sworn someone on this board said that Ziggy or someone else said that the gyro's can be recalbrated by doing some combination of stick movements but I wasn't sure so I thought I'd ask.

    thanks

    Dave
     
  2. Brad Meier

    Brad Meier Active Member
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  3. Dave King

    Dave King Well-Known Member

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  4. Brad Meier

    Brad Meier Active Member
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    Sorry, I was trying to reply while in the cockpit about to push. Here is where that link leads to..


    "Calibration before first use/modification or new firmware
    Perform ACC Calibration:
    It is *very* important that the MK is as horizontal and still as possible, shim it up so the arms are perfectly level, then program EEPROM by moving left stick to upper right corner. (max throttle + max right yaw)- you'll hear audible confirmation.
    ACC only needs to be calibrated once, after that you can start from an embankment or sloping surface without problems. The saved values will be loaded at every bootup."

    In other words, left stick up and right saves level
     
  5. Brad Meier

    Brad Meier Active Member
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    I also probably didn't read your full post but if your not in GPS hold while flying, and the ACC calibration is off, you will notice a significant drift with no control input and no wind.
     
  6. Gary Haynes

    Gary Haynes Administrator
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    Likely that an in advert antbump of the stick reset the acc. Or if you did a software update as Brad mentions.
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Also, Dave, I think you may be confusing two concepts: The Accelerometer (ACC) calibration (which you do with the FC level as you point out) and the gyro calibration, which you do before you start the motors and with the bird on the ground, but not necessarily level.

    You can do both with the sticks unfortunately so you can certainly inadvertently re-cal the ACC without the FC being level.

    Just as a convenience to anyone reading this thread in future:

    Calibrate ACC : Left stick to top right hand corner. (Only do with copter level, and only needs to be done once.)
    Calibrate Gyro: Left stick to top left hand corner.

    Hope this helps
    Andy.
     
  8. Dave King

    Dave King Well-Known Member

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    Thanks for the clarification. Yes I meant calibrating the ACC not the gyro. I could have sworn that someone found something that reset the ACC other than with the left stick to top right hand corner.
     

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