Roll gets unstable when pitch is 90 degree up or down
  • Someone else had similar issue which I'm having with 2-axis gimbal. Discussion did end before reason for this was found and therefore I post this problem again.

    My 2-axis Gimbal works just fine in hand and when controlled via RC In range of +80 to -80 degrees. But Roll axis gets very unstable and begins to swing around when Pitch angle is +90 or -90 degrees. Instability of Roll axis begins from about 84 degrees. or -84 degrees respectively. When Pitch is driven over -110° and +110° Roll gets steady again.
    Details I think might be helpful are following and I provide anything needed more:
    - FW 2.66 b0 latest attempt
    - FW 2.63 b0 earlier attempt
    - All settings returned to default and only mandatory settings are applied (RC - main PIDs - Orientation of sensor - 6 pos - 12 poles)
    - 6 - pos calibration is done
    - Board is new official from Basecam with encoder support. Encoders are not is use. FW is for without encoders.
    - Camera is very well balanced and it stays where is when motors are powered off
    - Motors are T-Motor GB4106
    - Camera is Canon EOS M with Canon 22m f2.0
    - IMU sensor is mounted with M3 screws to laser cut holes of camera stand and is very well aligned
    - Settings file, a video and screenshots are here: https://tinyurl.com/y7tafovj

    Pole count 12 I'm not 100% sure because I didn't find any good source for it but one site told it is 12. Auto detect gives very random results.

    Could someone help me to find reason for this or could this possibly be FW issue.
  • Hi Teppo,

    usually motors don't have 12 poles but 14. Try to set 14 poles and try again. AUTO function doesn't give correct number of poles everytime.
    btw, if you not use encoders, do you use frame sensor? If not that can be source of your problems.
  • See the euler angles and there is couple of options for 2 axis setups under stabilisation (att the bottom of the page) test them.
  • Thanks for replies! I try these in the evening. I Googled again and found another site where is said like this:
    - "No. of Stator Arms (N) 12No. of Stator Poles (P) 14"
    - Another site said "12/14 poles"

    So at least pole count seems to be wrong.
  • I changed pole count to 14 and it didn't help. I also tried Euler angles and stabilization for 1-2 axis systems settings without luck either. According to manual those shouldn't make any difference in this case because this gimbal works just perfectly on all other angles but mapping angle and directly up. These settings made gimbal not working correctly on any angle, or didn't make any difference.

    Gimbal works flawlessly otherwise but "mapping angle" do not work for some reason.
  • I did the same, install the software 2.60 and it was solved. But, I would like to know what the inconvenience is.

  • @Ariellago, 2.60b4 without encoders worked, thank you!
    I'll post this info for support because I've been asked more detailed videos of the problem and therefore this isn't known bug.