Discussions

...so after a bad crash (http://diydrones.com/forum/topics/arducopter-disarms-motors-upon-switching-flight-mode-to-land)

I finally got my copter rebuilt, and am trying to get it to fly but it just wont act right any more. here is what has changed from the last build:

-new motors

-new arms

-re-uploaded firmware, re calibrated acel.

-ran through the setup procedure again

   -selected "x" mode

   -checked radio calibration, all responding as expected

-auto calibrated the esc's

today, i powered up, waited for the gps to lock, then armed the motors. took off just fine, needs some pid tuning. however; once i got it up in the air, it seemed that the roll and pitch inputs were either swapped, or it was flying in a "+" configuration. I got confused, lost orientation, and wasnt able to get a sense of what my controls were doing, and wouldnt have been able to control it anyways, so i switched it to land. It stuttered for a while, then chose a real mad pitch, and crashed. luckily it had alot of horizontal speed and not much vertical speed, so all that broke was a prop and a cheap 3d printed motor mount. 

I am still new at looking at these logs, can anyone help me out?

What i can gather: 

-the logs confirm that it is expecting "x" flight mode

-EV 25 is present - so i know it got a lock

-it looks like the gyros all went crazy at line number ~6500

what happened here?

EDIT:some more info: I used the failsafe window to see the motor output response with the stick inputs. i left the copter on the table with the props off, and all seems to be responding to inputs as expected with "x" config:

stick right spins up motors 2 & 3

stick left spins up motors 1 & 4

" " up " " 2 & 4

" " down " " 1 & 3


...but...


when i pick the copter up, and move it round its axes, then set it back down on the same table (the table used to set acel level)), the motor outputs do not return to equal values. is this correct? it seems like they should all at least settle to equal values.


this makes me suspect the esc's. but idk. any thoughts?


i know its a crappy video, and i dont know if it helps, but i made a quick cell phone video:

https://www.youtube.com/watch?v=bGSWZVoGE9o

EDIT2: so in chasing down this misbehavior, I tried tuning the PID's after class today. i think i got them to a pretty good spot, but i notice while i was tuning that the copter would have bursts of semi-sustained, much higher throttle and motor power output. So i would be tuning just fine, and the copter respond (what seemed to be random, intermitent timing) to some inputs by revving up the motors for maybe 1.5-3 seconds. 

I am using a power harness as opposed to a pdb. could this be a current ripple?

2013-06-05 10-32 2.kmz

2013-06-05 10-32 2.log