As the topic says: What went wrong?

Haha, when you say it comes down, are all of the motors stopping at once? And is it consistent in any way it happens; only when throttle is over a certain point, only after it has flown so long, completely random, and ect.
 
All motors stop but it seems like its dropping left first. It happens a few minutes in the flight ( ~4-6 min?) but sometimes it does not crash at all for 2 flights or so.
After the crash i can simply re-arm and the motors react correct to throttle inputs.

The throttle has no influence.
I took the props off, throttle to ~25% and then i shaked the copter a lot to see if movement or vibration could be a reason -> no result
throttle at ~50% ->no result
As i said i can't reproduce it. It happens randomly.
 
HI mate the KK does the same thing if a motor stop as it tips over the board bleeps and all motors shut off
 
I agree with Neil, sounds like one motor or ESC is shutting off for some reason. I did not know the KK shut off other motors if one failed, but I'll keep that in mind haha.
 
While testing i came across another weird problem. The Front right motor spins up ramdomly without throttle input, EVEN when disarmed. (is that even possible???) I changed front/right motor with back/left motor and the random spinn-ups are still front right...
That would mean something esc-side is not correct...

So what do i have: Something causes the front/right motor to spin up randomly. The copter shakes a lot so i try to bring it down. The ESC has somehow lost controll over it and then the naze shuts down the other motors. -> Crash.
Now grounded the Motor still thinks it should spin up randomly.

But that would not explain the crashes where it was just hovering and fell out of the air without shakes or warnings.
 
Check to see if it is connected correctly, and has no shorts across pins. I recently had a problem while plugging my motor in that it spun up for no apparent reason. Try plugging the motor directly into the throttle input (should be channel three.) It should act normal, if not your is for sure in the ESC.
 
Problems just got worse. I disconnected everything from the naze, then bec and one motor connected to the rx. The PDB got hot and one esc made the heatshrink split. On that esc one of the small black boxes (fets?) desoldered and moved a little. I guess that esc is dead now. The front right motor still spun up randomly.
 
Hmm, defiantly sounds like a short. Try to find the short before adding power, and you will need to assess the damages, to aid you in finding the short you could test for for continuity among positive and negative wires.
 
I checked + and - for continuity but there is absolutely NO connection between + and - at any point before the ESCs. I will now check the ESCs individually to see if some are still working. That will also tell the reason for the random spin-ups but not the reason for the random crashing, since i had that before the spin-ups too....
 
Tests done. ( Its Exam time so not a lot of time :/ )

Motors work flawless, one ESC dead, 3 others are fine...
What have i done to prevent the random crashes:
- different firmware on KK, different FC; tryed Baseflight and Cleanflight
- changed Power Distribution 3(!) times!
- changed ESCs
- checked Motors; flawless
- changed rx power system
- changed the whole rc system
- changed frame
- tryed different LiPos

The above changes have NOT helped ANYTHING at all! Im starting to loose options......:(
 
This is where a black box would be handy, sadly the KK does not yet support this.

From what I read the only things that have not been changed are the motors?

With the parts you have changed you could build a second quad, is it possible you have a cold solder joint somewhere? Make a list of the things that are the same.
 
it's not an ESC/Motor sync problem is it, same as I seem to be having in my thread here

After all, as George says, seems the only thing you've not swapped out are the motors
 
I know i could have build a second quad till now, but it kind of disturbs me that i can't fix it. o_O
Things that are left from beginning:
- Screws for the motors
- Motors
And i am still using the same solder, double sided tape and heatshrink.
 
If it was a motor problem i would have noticed it by now and the quad would not be flying perfectly again after crashes....
 
Maybe, but sometimes a cold solder joint can loose connection due to vibrations and later regain it just fine, if it is on the 3-phase side of the ESC it would cause it to act very odd, if it were before that on the DC side it could be the cause of it spinning up, and crashing randomly.

Do ANY wires get a bit warm?
 
Upon closer inspection i could not find any indications for cold solder joints (on fc, pdb and escs checked) although i think of that too by now. But i can't be that unlucky to have a cold solder joint in 2 fc or in 3 Power ditr. or in 2 sets of ESCs........... Or can i?
And just for note i had no spinups with the old escs.
 
Hi mate you said you never had this on old ESC , then it points to an ESC problem , change ESC or the coding on the ESC and see if that fixes the problem , I know you said you changed the ESC was it with the same one if yes this will have the same code and may be the problem
 
You must log in or register to reply here.
Back
Top