2 devastating crashes in a month using Wookong

Cornforth Images

Cornforth Images

Member
aForcefulThrust

I hope that we both can regain some confidence in these devices.

Quantumlight

I read the manual and noted the part about the controller not working well at polar latitudes. I scoured the forums for more information and consulted my dealer who assured me that as long as I had a GPS signal my copter would fly. My initial hovers reassured me that it was OK to lift up to 10m, which is when I lost control. I will definitely put in in the time to learn to fly in Manual from now on. Still, I did not expect my 2nd copter to flyaway back home in Seattle. At least this next build will be with all new equipment.

mbsteed

I now realize that after 2 flyaways. After my flyaway in the Arctic, I did not anticipate the second crash also being a flyaway even though I was back home. There is a park not too far from my house where people can fly rc. However, based on what I have observed during my 2 flyaways, the copters can still fly a long way on their own very quickly. Scary. What I ultimately want to do is use these devices in remote locations. Thanks for your advice.
 

rameshtahlan

rameshtahlan

Member
Hi all
have been using WK M for over a year now. Using on my home build OCTA, wheel dia 800mm
was flying on GPS, and height hold at 70 meters height.
Had the Z15 go pro gimbal and Hero3 on it.
suddenly it nose dived and crashed.
Gimbal damaged.
camera safe
of what ever was left, powered up, all seem to work ok
tilted the IMU with my hand and motor response was correct.
Now its a mystery.
One thing is sure,
can't use this particular WK M again.
Fortunately was not using on my Heavy Hex with Canon 7D on it
I have read many posts where something sudden has happened.
My system is not the one that was recalled by dii.
another friend of mine had the came thing happen from 22 meter ht.
and in both cased no Tx response.
I in fact opened full throttle to try to reduce the fall rate... no luck.
have written to dii.
Hope some kind of reply comes
Regards
Ramesh Tahlan
 

P

ProPilotWannaBe

Member
Sorry about the loss. We've all had those disheartening accidents and hopefully you will find the root cause. Out of curiosity, why would you say you can't use the WKM anymore?
 

rameshtahlan

rameshtahlan

Member
Hi ProPilotWanaBe,
I have been trying to figure out the root cause, but just can't understand how.
The octa was hovering perfect, on height hold mode.
and on her own nose dives into ground.
That is why i said won't use this particular WK M again on a camera mcopter. How many cameras can one afford to loose. but yes, its an occupational hazard.
A new one is on the way.
Unfortunately WK M does not have a data recorder.
The Gemini controller by Zero UAV has a data recorder, and in case of a crash one can send the last 30 sec of data recorder for them to analyse the fault.
Ramesh Tahlan
 

soler

soler

Member
The DJI MK iOSD has a data recorded, not the mini. unfortunately there is no date stamp on any of the records so when analysis logs you need to work out which one to look at.

rameshtahlan said:
Hi ProPilotWanaBe,
I have been trying to figure out the root cause, but just can't understand how.
The octa was hovering perfect, on height hold mode.
and on her own nose dives into ground.
That is why i said won't use this particular WK M again on a camera mcopter. How many cameras can one afford to loose. but yes, its an occupational hazard.
A new one is on the way.
Unfortunately WK M does not have a data recorder.
The Gemini controller by Zero UAV has a data recorder, and in case of a crash one can send the last 30 sec of data recorder for them to analyse the fault.
Ramesh Tahlan
Click to expand...
 

rameshtahlan

rameshtahlan

Member
soler
thanks for that input.
its gonna be one hell of a time to figure out which log. hope its also in graphical form, that way at least the altitude slop will show near vertical loss of ht from 80m to ground in less than 4 seconds.
but will certainly go throughout it.
may just come out with something.
i don't remember the manual shooing what parameters r recorded. cause if its just basic flying parameters, then it useless.
if it gives some parameters of internal functioning, then that is where the money is
lets see
thanks again
Ramesh
 

flyonix

flyonix

Flyonix
Sounds like an ESC fault to me, we have had a couple in the past, and it always comes back to the ESC... never had any issues with the WKM..
 

rameshtahlan

rameshtahlan

Member
Hi flyonix.
I have had esc failures in the past, and the mcopter would start to rotate first, as i would see the rotation start on my video monitor first and then realise there has been a failure up there.
and while coming down would start to wabble also and go out of control
However in this case, there was no rotation (yawing) or wobbling... it just tipped to a bit of right, and nose down and came down like a brick. all motors and props were running throughout.
In the esc fail or motor fail cases i had in the past, i could see one prop stand still when i would look up after seeing the rotation start on my video monitor.
i am generally at 100m to 300m height.
Thanks for the input though.
will put this WKM on my quad and just fly it .....
Ramesh Tahlan
 

flyonix

flyonix

Flyonix
We have had problems with ESC where they just speed up dramiticcaly for no reason, causing the machine to 'nose in' and head in a general direction, this has happen to us a few times with one machine. we stripped the props from it and had it idling on the bench, and every so often we would here one ESC rev higher, as if it was stuck... we changed the esc and have never had a problem since..
 

djw43

djw43

Member
flyonix said:
We have had problems with ESC where they just speed up dramiticcaly for no reason, causing the machine to 'nose in' and head in a general direction, this has happen to us a few times with one machine. we stripped the props from it and had it idling on the bench, and every so often we would here one ESC rev higher, as if it was stuck... we changed the esc and have never had a problem since..
Click to expand...

sorry Ramesh about your accident, and thanks flyonix for the helpful info.
 

rameshtahlan

rameshtahlan

Member
flynox
thanks for that input..
could have have thought such a thing could happen
well
have a lot of test to do on escs before i take the machine up again.
many thanks buddy
 




L

leofuica

Member
Hi, for me sounds like a lot of vibration to the IMU, because this issue make crash every S800 and F550, yaw - turn - accelerate - down - crash with out control with RC ( not responsive)....
 

rameshtahlan

rameshtahlan

Member
Leofuica.
thanks for that input about vibration.
I am now taking measures to reduce vibration on IMU
earlier i had installed it the way dii says - just install with the double sided tape provided as damping is done internally.
but on this particular Octa i had used the damping pillars that come, the black ones with threaded holes to hold it on the base plate, and then hold another plate on top on which to mount the IMU. But i guess vibrations do get through to the IMU.
but now i have ordered the new Vibration Damper Kit by dji, which i just received, so making adapters to use it on my home made octa.
http://www.buzzflyer.co.uk/DJI-S800-Upgrades/DJI-S800-Vibration-Damping-Kit/p-203-2563/
I got the ones with blue balls.
Many sites are giving the ones with Black balls.
what is the difference.
Ramesh Tahlan
 


rameshtahlan

rameshtahlan

Member
Soler,
some help needed.
just went throughout the iOSD MK II manual
can't find how to access the data from it.
is there any link where it explains how to access the data from the iOSD
Thanks
Ramesh Tahlan
 

P

ProPilotWannaBe

Member
rameshtahlan said:
Soler,
some help needed.
just went throughout the iOSD MK II manual
can't find how to access the data from it.
is there any link where it explains how to access the data from the iOSD
Thanks
Ramesh Tahlan
Click to expand...
Ramesh, you simply plug in the USB cable to your laptop and start up the iOSD PC Software. One of the first questions you are asked is if you want to configure the iOSD, or view the data. If you pick to view the data, the iOSD becomes a USB data drive and you can copy/view the files. The iOSD PC software does give you a viewer of the data, but it's pretty basic. I've seen people post software they've written to analyze the data and provide it in a more meaningful format. I have pretty much stuck to using the DJI iOSD PC software and has worked for me.
 

rameshtahlan

rameshtahlan

Member
ProPilotWannaBe
Cant thank u enough for this information on how to view data from iOSD
thanks a ton.
Gonna view in a day or two.
doing some work on my table top mini lathe and mill, to make adapters to install the Vibration isolation dampers.
Ramesh Tahlan
 

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