Discussions

Big X8 Strange Behavior

Posted by Antonis konstas on December 13, 2015 at 9:31am

Hello to all 

 

I  build a big X8 and i suspect some think happen with my rc mapping when  octo starts  it feels unresponce  with  big corrections  and hard landings result and some flips whatever i do  in P doesn’t  affect  the system  so my next think is the rc mapping  i use sbus futaba  receiver  direct pinned to pixhawk  but my rc in  and out in channel 12 and  4   look strange also  the roll and dess roll looks opposite 

I enquiry the LOG 

 

Any comments are welcome

https://youtu.be/VW37goiZcRg

3691261205?profile=original

39.BIN

39.jpg

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Replies

        • Antonis konstas > Antonis konstas December 17, 2015 at 11:03pm

          3702803979?profile=originalboth is crashes  with same setup  difference between them  8 days and a new  flight controller  the big difference is  in 24  log quad flies for one min  smooth and problems start when i change flight mode and in last one i just try to fly to stabilize only  the newest is at left side 

          • Developer
            Randy > Antonis konstas December 17, 2015 at 11:36pm

            The 24 log certainly looks better.  The main problem shown is that the pitch control is very bad.  It's difficult to say what Rate Roll/Pitch P terms will work but there's a wiki page which shows how to use Ch6 tuning knob to adjust the tuning in flight.  Big copters generally need higher P values so you might just try increasing Rate Roll/Pitch P from 0.15 to 0.25.

            If 39.bin is a more recent log then I think it would be best to go back and recheck the motors are all wired up correctly, spinning in the correct direction and that the propellers are on properly.  It certainly seems like a mechanical issue though, not a software problem.

            • Antonis konstas > Randy December 17, 2015 at 11:42pm

              Dear Randy  

              First of all  thank you for your time 

              24 log it was the first crash  39  was the last crash as i mentioned   the  setup is the same  only difference was the flight control due to old one it was  defected in IMU  so according answer form 3DR support we take  a brand new FC  this is the reason it is  strange  everything in the bench works flawless  and it is very curious  this machine is not fly i try to adjust pids manual via ch6 knob and then if this works i try to do autotune   if this not work i suspect one or more esc is broken but i dont know how to examine them because  as i say in the bench works like charm  you can see video here  from yesterday test 

    • Antonis konstas > Randy December 17, 2015 at 10:37pm

      randy i actually take off in 50%  and at 1540 in  throttle range in pixhawk this is very strange you think maybe  esc are not calibrated correct in sbus configuration?

      I made now stand alone  calibration to be sure everything is calibrated correct 

  • Antonis konstas December 17, 2015 at 6:31am

    pictures form electronic setup

    DSC00306.jpg

    DSC00307.jpg

    DSC00310.jpg

  • Antonis konstas December 17, 2015 at 1:44am

    Guys please this is a serious problem i ro know  what to do 

  • Antonis konstas December 14, 2015 at 10:35am

    None can answer ?

This reply was deleted.

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