Unstable on launch Hex Aero says it's bad Firmware

Hello @ all,

I’m flying a F450 Frame with Carbon arms, Hobbywing 40 Amp ESC’s. T-Motor 2814-10 KV 770 and
PixHawk2 .
Everytime when i’m powering and arm the copter ( Stabilized ) and give just one click of throttle the motors
are accelerating very fast and hard. When i try to start the copter tillts left or right very fast and it flips. Same whe i’m traying in loiter. I’m disarming the copter and rearm it with the throttle stick hold in right positio for 10 sec. The LED’s starting to flash and AutoTrim starts, I’m arming the copter again switch to loiter and it takes of without any problems. It flys great when it is in the air.
Do i miss something on startup ?
How can i get rid of that ?

I have attachted a LOG file. 2017-10-04 18-02-40.bin (906.4 KB)

Thanks in advance

Just finished putting together a new hex and I have this exact symptom. Slightest touch of throttle and motors scream to life. My previous quad with the same components did not do this. Only thing different is the quad was on 3.5.2 and now I’m 3.5.3. I’ve been through every parameter and can’t fix the behavior so I’ve come here. I’m holding the hex down with my foot experimenting with settings. Here’s a log of the last attempt.

I’m betting it’s something real simple.

“Test all motors” and “Test all in Sequence” buttons do not work.

Test all motors spins 3 or 4 motors (random). If I press the button a second time while some motors are spinning, then all motors will spin.

Test all in sequence spins motor A and nothing else.

Testing each motor manually works fine.

Don’t know if this could be related.

Same here with the sequence: Only motor A spins. Nothing more. Was the same in v.3.4.6 and following versions too

well my issue turned out to be uncalibrated accels… really not sure how they became uncalibrated, but clearly I goofed at some point… hope this helps you surbi

I have writen a Mail to Hex Aero. Here is the answer…

Dear Jan,

Thank you for your email.
From the logs it seems that it flew great sometimes.
But will diverge during takeoff sometimes (the desired attitude and the actual attitude do not follow each other well).
It seems to be a firmware issue where sometimes abnormal signal is sent to the ESCs.
Please post your log onto our Facebook group and/or the ardupilot forum for arducopter firmware: https://discuss.ardupilot.org/c/arducopter/copter-3-5 , where developers are able to look into the issue.

Best regards,

Betty

I hope a developer from here can help me…

Kind regards: Jan

make sure ground effect isn’t affecting the quad… reduce P gains to test