8bit/3axis Roll with slow oscillations
  • Hi all, was using a tuned by me 8bit/2axis controller, 2.40b7, that worked pretty well.
    Been trying to tune for a few days now an 8bit/3 axis controller with slow oscillations on roll axis (like slow walk), not vibrations,
    controller came with 2.40b7 installed, would a ferrite ring help? or any other twist? already tried low/med/high power but didn't help.

    Thank you in advance!
  • +1 any thoughts?
  • What kind of PID do you have, does it do it when follow mode is not activated. Have you all RC channels disactivated?
  • Hi Garug! In my case, fails when Follow Mode activated.
    I'm using Pitch Tilt channel on RC only, and FC Roll with AUTO gain 8, tested FC Roll Off, didn't help.
    On Real Time Data I can watch the roll line making waves when I move the frame (quad) on Yaw axis, but the Roll horizon keeps steady on GUI, in real life, on air, horizon swings.
    Been testing PIDS and Follow mode values, got a little better when raised power.

    R 9 0.24 15 150 0 14 2208 motor
    P 9 0.4 9 100 0 14 2208 motor
    Y 25 0.27 20 150 0 Inv 14 2804 motor
    limit acc: 100 Z -Y

    Gyro trust 100 Accel comp √ Deadband a c 0

    R AM -60 60 10 LPF 3
    P AM -30 100 50 3
    Y SM -30 30 10 3

    Follow Mode
    √ Disabled
    √ Estimate F A from Motors
    √ Follow Yaw
    Deadb degr 4
    Expo c 50
    Yaw offset 4 speed 10
  • What FW is that, It could be the follow offset auto. have you performed it?

    Sometimes after beta testing some FW etc. I have had strange issues. Erase EEPROM has helped to those. Before you do it save the EEPROM and save the profiles. Erase EEPROM will erase everything.

    I have not however used the old profiles or EEPROM files, but set the hole gimbal from the start up, everything, and that has solved the strange issues.

    Note: the first thing really to make sure is that the gimbal is well build and IMU well installed. If the axis are not 90 degrees to each other and if IMU is not parallel to axis, it will not work well.

  • Firmware is 2.40b7, yes, follow offset performed,
    will try erase EEPROM to start from scratch,
    but don't know how to do that erase on 8bit controller,
    any link? Thank you !
  • I do not remember, but if it is not obviously visible on the menus, then probably not supported on 8 bit boards.

    Maybe the 10 press on the button works on 8 bit, but as I understand it only sets factory defaults, so not the same thing as erase EEPROM. (but after it it is necessary to set up everything)

    Sometimes it is just good to set everything up carefully from zero. It happens for me too that I get wrong inverted, wrong number of poles etc. Very important to do the basic setup carefully.

    IMU calibration is also important. Note: normally gyros are calibrated during startup. during this calibration the gimbal must be stationary or there will be problems.

    I disable the gyro calibration at startup, and perform it carefully when needed (if there is drift).
  • Yes, no EEPRON erase on this GUI, checked the gimbal arms and were a little off 90 degrees, that helped too. Will test gyro cal on startup off, always used on.

    Last question (hope), I use IMU sensor attached directly on top of camera (GPH3+) aligned with lens, horizontal way Z -Y, didn't give me issues on two axis controller so I keep it that way, could this be an problem with 3 axis controller?

  • As long as all axis are correctly configured and especially forward direction is accurately set and firmly installed, it is fine.