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About to lose it... trouble with tuning
  • Hi All,
    I'm finally about to lose it with this gimbal but figured I'd reach out for some help before calling it quits.
    This is my 2nd DYS 3 Axis Smart Gimbal and for some reason this one has been fighting me for almost a year now.
    I just can't seem to get it so smooth out. Once I fix one problem, another keeps popping up.

    What's going on is, when just hovering or flying very, very slowly, it seems to be working ok but I get a strange twitch in the Pitch of the camera. I'm thinking this might be from the RC control of that channel as I don't notice it happening when I'm working with it on the bench and the TX is turned off.

    Then, once it's flying around faster I'm getting all sorts of oscillations. Not so much jello, but just rough looking video. I'm also getting jumpy Roll and Yaw movement when I stop pitching the Quad forward or backwards. I've been working my PIDs and Power settings all along trying to get it right but I haven't figured it out yet.

    Below is also a link to a video using the settings below:
    https://youtu.be/EIgDjp34DT0

    Here's my current setup:
    Turnigy 9xr Pro running a Frsky X8R in S.Bus mode
    4s Lipos
    Tarot 650 Quadcopter Frame
    Sunnysky X4110s 580kv motors
    T-Motor 15x5R Carbon Fiber props
    DJI Naza M v2 FC

    I have the Gimbal hanging off the Camera Rail with the battery Suspended underneath as well.
    The Rail, and Gimbal are all mounted using Tarot Rail Bushings (or whatever they're called).

    So here's all that I've tried so far.
    - Balanced Gimbal
    - Performed 6 Axis IMU calibration and Gyro Calibrations
    - Balanced Motors and Props - Was able to get most major vibrations out but there's still some high-end vibration present, however, I can barely feel it on the gimbal.
    - Moved battery to Camera Rail to try and absorb any vibration.
    - Using bushings instead of the plastic Tarot Rail Clamps to mount Gimbal
    - Upgraded Gimbal dampener balls to larger DJI Brand
    - Added anti-vibration standoffs to Gimbal Mounts

    I'm sure there's been more, but off the top of my head this is what I can remember. Like I said, this isn't my first DYS gimbal so I know how to properly setup, calibrate and tune them but for some reason, nothing's been working. I can't determine if it's an issue with my Quadcopter or an issue with my tuning.

    I've attached photos of my settings as well as my gimbal mount setup.

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    Any help is greatly appreciated!!
  • I have been experiencing a very similar problem on an almost identical setup.
    After commissioning a new but similar 2-axis frame hanging from the rail.
    I can not increase the gains enough for stable tracking on Pitch without introducing high frequency noise into the loop.
    I am using a 2-axis 8 bit non-genuine board w/ 2.408b firmware.
    Even with low power and gains, oscillations are easily induced, both high frequency and an odd twitching motion.

    Things I have tried and tested:
    - smoothened 12V power supply
    - 6 point Acc & Gyro re-calibration
    - new motor + measured phase resistances (13 ohm for DYS 2208-70 motor)
    - swapped Roll and Pitch terminals from board, problem stays at Pitch.
    - Gryo Low-Pass Filtering. worsens the problem oddly enough.
    - ferrite ring on cabling
    - different cabling
    - reflashing firmware
    - external FC acc signals.

    Problem remains; bad tracking, twitching and high frequency jitter.
    Turning the motors OFF doesn't show any more noise on the Pitch channel for the acc and gyro readings than the roll, so the IMU seems fine.

    *** I noticed the AUTO DETECT function consistently designates 15 poles to the pitch motor, while correctly deducing 14 poles for the same Roll motor.
    This suggests a bad motor, however I ordered it brand new to solve this very problem...

    Sorry to not be of help, if you solve plz lemme know!
  • On such small gimbal it is super important that all axis move freely. Most often inexpensive motors have bearing problems. It is best to test when nothing is attached to the motor, it should spin free.
  • I still haven't solved this.
    Tried, tested and swapped the motor but problem remains.
    My best guess is a bad board, but swapping motor outputs doesn't make a difference so even that seems odd.
    Will order a new board i guess