yaw not operating correctly

on my quad, pitch,roll and throttle are working fine. When in stabilize the yaw appears to have the effect of moving along the 5oclock to 11 oclock axis, although i have to land fast before it crashes. In stabilize with simple mode enabled the quad immediately yaws after takeoff. All other inputs seem to be ok.i dont think its a compass issue.  i have calibrated the compass and transmitter. The motor test in the terminal is operating as expected. The props are matched to the user guide.the frame is an x config.

Any ideas as to what is wrong?

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    • MR60

      If you have 50% battery left, then it isn't your battery.  It's the ship design.  The ship is too heavy for the rotors or the rotors are too small for the ship.

      Its the 80% throttle to hover.  It needs to be 50% or less.  The batteries prove it.  At 80% throttle, you are pulling so many amps that the voltage of the battery drops significantly, making it think it's empty so your ship slowly falls out of the sky.  When the amp load is removed, voltage immediately goes back up showing 50% left.

      Remove weight or change the rotors. 

    • MR60

      First - Rebuild your copter is a must

      a) hover should never take more than 50% throttle.  the ship will be uncontrollable in moderate wind and take way too many amps.  Thus:

         ... remove weight by doing a weight study and replacing parts with lighter components

         ... or change the rotors (motors and or propellers) so they are sized to carry the weight.

      b) ensure that your ESCs are Simon K firmware (it sounds like they might be).  The behavior at the end of battery life as voltage drops is the copter will slowly fall out of the sky.  So you increase throttle to counter.  Finally, there isn't enough % recovery left so it can't do a yaw correction without falling more out of the sky.  To see this, enable CURR and track your volts and amps.

      c) ensure that your battery has a high enough C.  As the battery voltage drops, the ship becomes more efficient (about 1 to 2% more).  So the ship will stay aloft at fewer watts.  but as voltage drops this means the amps must increase, taxing the C of the battery.  a chemical barrier builds up and the ability of the battery to deliver the watts drops off suddenly.

      So it sounds like a typical case of going through a battery too fast.

    • Good news. I used some old 3000 mah batteries and i can get about 5 minutes flying time. It still hovers at about 70% which is not right. So what did i change in the last few months that could cause the issue? i remember i bought new motors and props. back then i bought these motors and these props. Now the motor spec recommends 12X45 as opposed to the 11X50 i bought. Does this explain the significant power loss? i am going to ask a separate question on the topic.

    • Hi forest. I have four of the exact same batteries. So i agree, the symptoms sound like battery issues. Every battery has very little power. I believe it is unlikely that all four batteries failed at the same time. Is there some way i can prove that it is batteries or test the batteries? After landing they are still showing 50% charge left. 

    • Hi Forest,

      So i recorded the flight on my gopro at 250 frames per second and at 1080p 60fps. I think i can see the back right arm shaking - it's really hard to tell. One thing i believe may be happening is if you look at the way the motor is mounted in my images above the motor is on the aluminum piece that came with the motor and then that is mounted on the frame. I believe that that aluminium piece is not even on the frame. Anyway - i went ahead and ordered a new frame - take a look.

      I was also looking for a gimbal to go with it for a Canon compact digital camera but unfortunately all the gimbals seem to be specifically for the GoPro. This one would be perfect for it but alas GoPro only. So the saga continues - i shall post back more when the frame arrives and i rebuild everything.

    • I have already removed the extenders. I am also going to put the gopro on the quad recording at 250  frames per second. I think ill do that before i make it lighter and afterwards. This should be interesting.....

    • Hello Damo,

      If I look to your Video, to me it seems that the weight of your system is to high.

      How high is your weight and what Motor / Prop application are you using?

      ...Or you need better Vibration damping to your Controller.

      I am using that one with big success..


      Best regards Peer

    • I am using a 5000mah battery these props and these motors

      The frame is a cheap chinese frame

      I also have landing gear and a Canon digital camera on-board and 5.8 GHz FPV gear

  • HI Damo, I know you said you calibrated each esc individually, but when doing so,

    did you go through the beeping tones to setup the esc (like you would with a programing card?) ie...

    setting up the brake type, (off!)
    battery type (NiMH)

    the settings below are my defaults each and every time I setup my esc's...



    1x briefly





    Battery Type

    2x short





    Cut-off mode

    3x short

    Soft Cut

    Cut off



    Cut-off voltage

    4x short





    Start Mode

    1x long



    Very Soft



    1x long1x short






    1x long2x short

    Factory reset

    I know most esc have the same settings but just double check with the type of esc you have before following the above.
    double check the piece of paper that comes with the esc, the list could be in a different order..


    • i have a 3dr esc 20 amp which i believe does not have these settings.

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