Hexacopter does not fly like before a crash


after a crash (beginner) I fixed a few broken things.

I also flash the APM 2.5 new because I changed too much parameters.

All mandatory things and settings and calibration done.

Now, during my first test flights I observe a strange behavior.

The Copter does not respond always as I expected while flying and

from time to time one (or two) motors sounds like they sudden accelerate

with a short screaming sound (for a second).

I attached the .bin file. Perhaps someone have a few minutes to look over the crucial values?

What is that for an (red) error message I see shortly before a fast (I was nervous) landing?

I tried RTL but the Copter drifted away, so I switched back an landed asap.

2015-08-02 20-02-52.bin

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  • Param Files

    13a august parameters complete settings RTL=1500 & calibrations WO ...

    19 August Ch 7 RTL and Ch 8 SIMPLE MOD with AUTOtune new assign.param

  • Hi, thanks one and all for your replies! :)

    Here is a new  .BIN file from the Auto_Tune flight yesterday.

    Is there something abnormal in the PID, gyro ?

    2015-08-19 18-47-05.bin

  • This is unlikely to be the issue but did your APM flight controller come loose as a result of the crash?  If the flight controller isn't securely mounted and facing forward, you could see similar symtoms.

    • Yes, the APM came loose but fixed again with the blue rubber damper.

      Always facing forward.

      At the bottom under the 5x5cm carbon plate where the signal wiring goes in is a 0.10mm sheet of MuMetal.

      Also under the APM shell.

      Only the white and black wires goes then to the ESC (HW XRotor 40A).


  • Hello,

    The 2 motor symptom: sounds like a compass issue. 

    1) Check alignment 

    2) Watch heading stability when not moving

    3) Do motor interference calibration. 

    4) ReCalibrate ESCs

    5) Try to observe the compass during the glitch. Hovering close to yourself might be a good idea or you could just strap down the hex and just run the hex for a battery or 2.

    Your Hex behavior sounds familiar. I had a clone board where the compass decided to constantly spin at a slow rate and caused similar behavior.

    Best of luck to ya. Upload a pic if you can.

    Check out my Hex, Stratos, at aerosurveysolutions.com.  40km(25mi) Telemetry link is just the beginning :D


    • This is my recent compass_mot calibration.

      (pic attached)

      I have a doubt: Could it be possible that I made a mistake installing a 0.10mm MuMetal sheet under the APM ??? The idea is to reduce interference, but now I'm wondering if that is not a good idea and lead to my compass issues ????            ☢

    • Well the interference is a bit high. 

      When I used APM2.6 with compass up in the GPS I had virtually no interference at all.

      MuMetal plate should not be generating anything, it is dampener. I'm not sure how this i happening if the plate is in between your APM2.5 and the current. 

      Not all dampeners are the same and I have not shopped MuMetal much. This could be an EMI not and EMR shield. 

      EMI is a signal shield, EMR shield from radiated magnetic field produced by large amounts of current.

      EMR is the kin of shield ing you are looking for.

    • Thank you for the info :)

      If the next test flights with some parameter mod's and different locations or without the piece of MuMetal does not improve the flight, I'll install a mushroom with GPS & compass and cut the on board compass.

    • FYI, if you ever want to send in your drone for repair, my company does repairs/restorations as well.

    • :)

      mmmh... I'm located in Germany, the shipping  costs would kill me (+ customs)

      Thank you anyway for the kind offer!

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