[ISSUE] (reproducible) Crazy yaw after takeoff

Hey guys,

i am running the newest stable firmware on my px4 on a hexacopter frame. There is a strange behaviour with yaw after takeoff some seconds afterwards. it rotates to the left. i regain control, but this should not happen.

my px4 is rotated by 180 degree. is there a problem? i have made a video for you. this happens every start.

LOG: http://logs.uaventure.com/view/sEBudvhYP8Gk6NVAjNDAKQ
VIDEO: https://goo.gl/photos/v6rp24NTL191cp7t5

do you know this issue?

This is a problem with EKF2 and an internal magnetometer which is strongly influenced by motor currents: http://logs.uaventure.com/view/sEBudvhYP8Gk6NVAjNDAKQ#Thrust_PLOT
Adding an external magnetometer should solve the problem, or you might be able to fix it by moving the FC (which one are you using?) further away from high-current wiring.

sorry but I do not have the answer to your question.

I’m wondering if you could tell me what frame you are using on your drone?
Did you make the long white “legs” yourself? The legs look like they make the drone somewhat more tolerant to low altitude falls.

It is the DJI F800 Frame. You are correct, it is a selfmade spring damper landing gear for low alt falls.

that looks very impressive! Not trying to hijack the thread you have here. Would you mind making a new thread with some pictures/instructions for how others may replicate you work on the damper landing gear? I think many people would find it useful during testing phases!

i think we can release our documents at the end of march 2017. are you able to produce the parts by yourself? they are custom made with aluminium.