Motor Failure

Cheshirecat

Member
I had my first motor out event on Sunday whilst in a stable hover at 280 Feet.
A big change in audible motor pitch was the first indicator, like it was fighting a big wind gust (except there was not very much) followed by some very twitchy pitching.
I chose to bring the aircraft down and during the descent it went into an uncontrolled clockwise Yaw which stayed that way until touch down.

Got it down without any danger to persons or property and intact but found the workload high so never actually noticed that a prop was not turning but also did not expect an X4 to spin with 1 motor out.
I suspected it was due to a motor failure and looking at the data logger for the Herkules quickly confirmed that motor 7 dropped out during the hover and never came back. In fact the datalogger on the Herkules is so good it didn't take long to confirm that the fault was due to a signal loss for motor 7 between the WKM and the Herkules (probable bad connection) but i shall swap the motor out just in case.

I could have made life a little easier for myself if i had put the WKM into Home Lock so a lesson learned on that one, but any ideas why an X4 would spin with 1 motor out?
my AUW is 9.2Kg on Tiger 4014 400KV and 15X5 props, hover is 55% at AUW so i expected enough reserve power to correct a yaw. The WKM didn't seem to be able to correct it in GPS mode but i could hold the Yaw manually in Atti by applying opposite stick. (seven sats locked at the time) either my expectations are off or i need to hunt down an imbalance in the setup.

Ideas welcome... Thanks
 

baja-king

Here for the ride :)
Hi Ches,

My only advice would be to change your motor config to the one that Andreas recommended rather than the DJI one.
 

Cheshirecat

Member
Yes i may try that once i (hopefully) get past assessment tomorrow (not an ideal time for a tech issue :shame:) the last time i tried the mixer config by Andrea's i could not get 2 of the motors to fire up in test mode but putting it back to WKM defaults cleared the issues so there it stayed.
Somebody else said ignore the test mode as he had the same but never had issues on a full start up but i am not sure if i am comfortable with that, did you run your SJ with Andreas setup when you had it?
 




Cheshirecat

Member
And hopefully you'll have some nice weather for your assessment :)

Weather is forecast to be near perfect, if i don't contact Resource and abort...I appear to have uncovered a rats nest of intermittent signals between the Herk breakout board and the Herk itself, i think i may have been lucky i didn't loose more than 1 on Sunday.
Working through it now.... No pressure:dejection:
 

Cheshirecat

Member
A quad would have simply flipped over which is why i would not operate one over say 2Kg
It is know as an X4 the Droidworks Skyjibians hence calling it an X4, but yes it's a Coax with 8
 

Quinton

Active Member
I had my first motor out event on Sunday whilst in a stable hover at 280 Feet.

You do realise that your "what if" scenarios will now be about 200% safer than before now you have had a motor out, as its something you don't think about until it happens to you.
This is why I CAN NOT understand these pilots who fly over people with a quad.
It will take time to get your confidence back in the machine, but after I had a motor go out on a Hex carrying a 5D on a Zenmuse, my train of thoughts changed completely regarding safety after it happened.

https://vimeo.com/87086309

You may have seen it before, here is it on video.
The good thing is you have a lot more confidence on a machine in the "what if" situation.
On the hex yaw control was almost completely lost, which would not be good on a windy day.
 
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fltundra

Member
Weather is forecast to be near perfect, if i don't contact Resource and abort...I appear to have uncovered a rats nest of intermittent signals between the Herk breakout board and the Herk itself, i think i may have been lucky i didn't loose more than 1 on Sunday.
Working through it now.... No pressure:dejection:
Get rid of that herk board, that thing is an accident waiting to happen.
 


fltundra

Member
What ever you think dude, single esc's are a much better config than that over priced piece of garbage.
 


fltundra

Member
And you speak from experience of a Herk III board?

...

Nope , don't need experience with that board to know you don't have any redundancy with a single combo board as you do with single esc's with logging capability.
It's common sense.
 

baja-king

Here for the ride :)
Nope , don't need experience with that board to know you don't have any redundancy with a single combo board as you do with single esc's with logging capability.
It's common sense.

Octo XL Herk III has redundancy...
 
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baja-king

Here for the ride :)
Well, speaking from experience of both Herkules III boards and KDE ESC's, I would take the Herk III any day of the week :)
 

Quinton

Active Member
I wouldn't mind taking my chances with a Herk board instead of 8 ESCs
Don't have one personally, but looking at all the videos/information on it it seems to be rock solid.
Actually this is the first fail I have heard of.
Agreed if it was cheaper probably everyone would be using it, I would love to have a lot less wires going on and have that much telemetry data in a freewheeling setup.
 

fltundra

Member
It's funny how the two top posters, one with an actual commercial business in the film industry are NOT using Herk boards.:tennis:
 


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