RC India

See the video to see it, the quad oscillates left and right , starts slowly and increases to the point that the quad literally flips and crashes.

The issue started only yesterday, nothing was modded or anything at that time.

I re-did the complete quad from scratch even re-tightened the frame, but still nothing helped.

PLEASE help me , I cant even guess what the reason of this madness is .. :(

Link:

https://www.youtube.com/watch?v=P9OuOCgJHsI&feature=youtu.be (https://www.youtube.com/watch?v=P9OuOCgJHsI&feature=youtu.be)

The video is private. Please post your current PI values as well. I suspect a hardware problem, perhaps loose or bent prop adapters

changed settings.


I've tried almost all; PI settings.. the quad used to work perfectly at the default settings ( 250 ones )
I reduced it to 40's range, and the quad was uncontrollable ..
now its gone mad :P

the props adapter, the props everything is fine , it happened all of a sudden :P

In which axis (Roll / Pitch) The quad is oscillating ?

Now that I see the video, I think it is something to do with the board. A bent prop adapter won't cause such regular oscillations. Please post your exact PI values as well as self level P values. Have you tried a factory reset? Are you sure you made no changes between the time it was normal and the time this problem started?

https://www.youtube.com/watch?v=lRbAqH-zjVs&t=3m20s (https://www.youtube.com/watch?v=lRbAqH-zjVs&t=3m20s)

after trying all I could, copied the values given here, the quad does move , nothing sudden, seems to have helped a bit but the PI values are too low now, not as responsive as i like it :(


@Soraj - the Roll axis , everytime ! ( Roll as in the left and right , right ? )

Parichya, Factory reset the board, load QuadX config. again, and do all tuning and calibration.

did it around 5 times ! .. nothing helped !

Have you run a sensor test? Try reflashing the firmware if possible.

sensors are fine .. cant reflash, dont have the tools,

this guy jaspreetguitar helped me A LOT, but he is busy now a days i guess :(

Try to Rake off and hover with out self level on, Just take off and hover it in low altitude.

at low altitude its almost impossible to do so cause of the turbulence, at higher altitude I'm afraid if the quad goes berserk again and crashes :P  :/

I meant 4-5 mtrs. Try with Self level OFF ..

tried that its was much worse than that ...
I messing with the values a bit more ...

have to out it n hold for 2-3 days due to the republic day scene .. :P

Gautam I saw your video, I would say that this is not safe practice, multis have so much power and it can easily hit your face. Better find some open space test there. I think it is not PI gain issue. FC mounting is key factor in this. So try changing your method of mounting FC. If possible add some damping. Is this KK2.0 or KK2.1?

1> The throttle was at a mere 20% so not much harm was there to be done, also, i already have been cut a lot of times so I know what where when is risky for an injury :)

2> If the FC mounting is the issues here, then why didnt it happen before, as I said before, the only reason I am perplexed here is that it happened all of a sudden and no change was made to the quad :(

3> What dampening ? Height ? and its the KK2.1

try Re-calibrate ESC if nothing wrong with controller board.

done that too, didn't help .

Gautam if current setup gave you decent flight then issue must be something with hardware or software glitch. You have to one by one check them.

try connecting only one motor at a time and hold opposite arm in hour hand. try to balance with gentle throttle.

dharmik - whats left to check ?

akhilzid - how will that help ?

that will reduce vibrations while checking,
can check each ESC and Motor.
can tune PIDs more safely and without loss of money.

one more thing i wanted to add , the board randomly loses the ACC Calibration values .. on its own ... happened 3 times now ..  im beginning to think that the board need a reflash i guess ?

It doesnt look like an oscillation, but swaying and drift and delayed attitude correction.

You can see how oscillations look in the embedded video which is a case of sensitive pid's leading to quick overshoot and correction cycle. Your issue seems to be a classic case of low PID values wherein copter behaves like a drunk and is slow in returning to level and eventually flips.

http://www.youtube.com/watch?v=02sBdqvvvUQ#ws (http://www.youtube.com/watch?v=02sBdqvvvUQ#ws)

So please try to understand how PID tuning works and tune it, because its impossible for anyone to suggest values as you built it yourself with your own specification and materials. Yet kk default PID's are good for anything between 350-450mm sized quad. A quick youtube search will land you with enough videos which explain how to tune a kk board. Meanwhile I just hope you have mounted the FC properly as the last time I saw your video, with FC mounted over battery is just a crash waiting to happen, as sensors hate vibration!

And what do you mean exactly by Acc calibration values being lost?How did you ascertain it n can it be reproduced?
Neither did you mention pid values, firmware are you using as some custom firmwares have multiple profiles with separate acc calibration.

Yes, it starts from the same but not so less.. angle wise it exactly like starts from a 20'-30' off each side and within 5-8 secs its on a verge of flipping completely !

I have an x600 frame, but I have mounted the motors on the near edge of the boom. I have seen almost every KK tuning video out there and none have been able to help me in this regard ( lowering the values to a very low values seems to do the trick but delayed response, and I loved the instant response i got from default 200 values )
The main thing that I dont get is that why is it happening all of a sudden ???

Yes I did mod the frame settings a bit but the issue started well before that ...

Regarding the ACC values lost, I mean :
I reset the board
calibrate ACC ( flat level all values zero )
alls good and suddenly after a while i see the board reading flat level as 4 and 53 !!
So i do the ACC calibration again .

regarding the PI values, the decent values that are sort off working now are the ones shown in the video ( gave a link in the earlier post )

here again :

https://www.youtube.com/watch?v=lRbAqH-zjVs#t=703 (https://www.youtube.com/watch?v=lRbAqH-zjVs#t=703)

and no im using the latest firmware nothing custom...

Hope you get it ?

No I dont get it! Because what Im trying to tell you is, using PI's from others setup doesnt always work. Every setup differs. Its not just about being same size or orientation. Now Im even skeptic about your tuning session. And the values you claim to use is very low.

Then you talk about increasing it to '250'. WHICH ONE? Is it P or I,limits or gains? Is it self level or ail/ele/rud PI values?

Anyways as far as I can see its bad pids or bad sensor data/board (doubtful), and there is nothing more I can suggest other than increasing P of 'self level' till the time you see oscillations as in the video shown in my earlier post, and then decrease it a bit until those oscillations go. That should get your quad flying if you havent messed with the PI values of ail/ele from default. 

OR

Reset board in menu Or reflash firmware which will get you back to default values which you started with!

.. umm ok i couldn't explain the PI values.. ill probably post the values i had and have now.

ONE QUESTION Still remains which really perplexes me .. WHY .. WHY al of a sudden when there was no change to the system ??

PI Tuning i get it, ill tweak it again , the question is why did it suddenly crap out :/

You should always explain about your settings and setup in detail when you are seeking help for an issue, so as to find the issue easily without doing too much circus. It just saves the trouble.

Since you say you didnt change anything in your system and if reverting back to default or previous or working PI's settle your issue, then one thing is sure that the flight characteristics displayed in your video was the result of weak pid's and they dont change by themselves as far as i know.

OR

Somehow your board keeps forgetting settings such as the acc issue, due to a damage,bad firmware flash, noisy power supply to board etc. I dont think its acc sensor failure because when it fails it does so spectacularly if in flight!