Radian creeping movement: tilt moves on its own

Discussion in '2 Axis Gimbal' started by Fulvio Tonon, Jul 25, 2014.

  1. Fulvio Tonon

    Fulvio Tonon New Member

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    Hello Everyone!

    I have a C8 HL (MK FC 2.5, BL 3.0, 6S). I have 2 radians in my 2-axis gimbal, and I have a MC-32 RC.. The roll radian is not connected to an MC-32 slider, and it works well, i.e. no drift. However, I’ve been battling with the tilt radian for a couple of days now (this is my first time using the gimbal)…



    Here’s the problem: I tilt the gimbal with the MC-32 slider assigned to the tilt (channel 10) up or down to the tilt angle that I need, then I position the slider on the center (0). At this point, the camera slowly keeps moving in the direction I tilted the camera (creep). If I tilt the camera upwards, the movement is upwards, if I tilt the camera downwards, the movement is downwards. This has nothing to do with balancing: I tried with a perfectly balanced camera (checked with no belts) and with an unbalanced camera.



    I checked the camera direction with a bubble level, and the bubble continuously moves until the level falls off: after 5 min, the camera is visibly pointing to a different direction. If I move my copter around by hand, the creep movement keeps going as it does when the copter sits on the bench. If I try to stop the creeping movement with my finger, I can definitively feel the force exerted by the servo, so it is not a gravity-induced movement: the servos are “instructed” to slowly keep moving.



    I connected the tilt radian to my computer and changed the gain btw 50 and 200%, and the angle trim btw -8 and 0.9, but the result is the same.



    I also checked channel 10 in the MK tool, and it is at 127 (i.e. 0 power) when the creep movement occurs.



    Would you have any suggestions? In my applications it is vital that the camera points to a constant tilt angle (e.g., always horizontal or always vertical) for the duration of the flight (20-25 min).



    Thanks a lot!



    Cheers!

    Fulvio
     
  2. Fulvio Tonon

    Fulvio Tonon New Member

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    One more thing: Current and Demand Angles remain constant during the drift, i.e. radian thinks that the camera is not moving.
    Thanks!
    Fulvio
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Fulvio -- I realize that it's a bit of pain to do this, but I would swap over the tilt and roll Radians -- you will need to re-program each of them for their new roles and reset their various parameters, of course -- but see if the problem still persists, or even moves to the roll axis. What this will do is tell us whether the present tilt axis Radian has an IMU issue or not.

    As you say, it is an important diagnostic clue that the Current and Demand angles remain constant....

    Andy.
     

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