Yaw starts shaking during flight
  • Hi,

    I have DYS BLG3SN gimbal with alexmoss 32bit 2.60 b4 software. I have balanced gimbal good (yaw doesn't turn if I flip frame let to right) and PID's are good. Another word my gimbal works as it should work on table, but problems come after I lift my copter to air, yaw starts shaking! After I did all calibration and so my yaw PID was approx. 40, 0.05, 48 and power 150. I drive it with 22V. I don't remember the excact numbers anymore., but with those values it work really great on my desk, but after lifting off yaw started to shake really badly. You could hear how copter motors was reacting to that vibration.

    So at first I looked and made sure that it was the yaw motor not the frame or gimbal that was shaking. Disconnecting the yaw motor shaking was gone and the gimbal didn't vibrate at all during flight. I dropped the power to 95 and it helped a little to vibration. I continued to adjust PID values. Now I have 8, 0.03, 12. Vibration is allmost gone, but still excists and affects to video. So I can't use the video at all. But there is not much power on yaw to keep in position in wind. Now the yaw start to turn about 30 degrees to right at flying. I think it's because the vibration maybe!?

    I don't know what to do next, this is driving me crazy. I have trying to get this gimbal work all winter so I would have nice smooth video. After all its so close but some stupid vibration, what I can't get to disappear, is still there! Do you have any suggestions what to do, PID's power etc? I have allso tried to hardmount the gimbal, but there was no difference to it.
  • Sounds like your yaw is not well supported, vibration dampening is too flexible.

    In any case tune the gimbal hanging the multicopter from the arms, so that the gimbal can operate like during normal flight. But flight batteries in so that the mass is correct, but do not connect the power to multicopter.
  • Hi,

    Ok. I was thinking that vibration dampening also, but I thought that it wasn't the reason. Because when I used cable ties to lock the gimbals plate to the frame so that vibration dampening rubbers where flat and couldn't work, it didn't help gimbal was still shaking.

    Well maybe I just have to figure out some solution to vibration. Maybe hardmount or something. I could change those rubbers harder, but where could I find right size rubbers? I bought some from Hobbyking, but they are way too small.
  • Do not think too complex. The yaw support needs to be reasonable good and the gimbal tuned when it is operating like during flying conditions, i.e. not standing on ground, etc.

    Try also using the LPF, tune one axis at the time, for yaw try also manual tuning, low LPF and high D. if any value goes during tuning to 255, use higher gain.

    If that does not work, then there is something else wrong.