F550 WKM went down like a sack of bricks!!!

yakjock

yakjock

Member
I was taking some pictures of a friends boarding kennels today with my F550 WKM & a GoPro & all of a sudden it just fell from the sky!
The weather was fine 25 degrees sunny 3-4 mph wind so ideal for flying. I was on the second flight of the day & about 1 minute in to the second flight about 10 meters up the copter just pitched left & rotated about 90 degrees to the right & slammed it to the roof of one of the kennels. I was in Atti mode & there was a very slight twitch of the craft maybe 20 seconds before it fell from the sky. It was on SW 5.12. At this time I cannot fathom why it went wrong.
It broke two of the arms, both the top & bottom plate, the pole which the GPS was mounted on, two of the props & the mount for the GoPro but a very lucky escape as it did not hit anything other that the metal roof of the kennel.

Just wanted to let you all know.
 

K

ksrimoungchanh

Member
several weeks ago, I had similar event.. though I was not that high. I was actually testing the Low Volt Landing, so I had the F550 at about 10ft hovering on GPS in front of a camera. My controllers was also in front of the camera with no one on them. Then like yours.. mine rolled and plunged toward China. Mine had been hovering for about 5 minutes before that.. and it already had some successful RTH when I power my TX off.

I send my WKM in and looks like it is on it's way back in on FEDEX now. Should be getting it today. Don't know the conclusion.. but I will be taking baby steps with this unit.
 

sim_io

sim_io

Member
I heard bad things about the 5.12 firmware specially on octos just falling out of the sky. Apparently 5.12a fixes those issues.
 

yakjock

yakjock

Member
Yes I had heard about the octo's but thought hat hexa's were not affected! I guess I was wrong!

sim_io said:
I heard bad things about the 5.12 firmware specially on octos just falling out of the sky. Apparently 5.12a fixes those issues.
Click to expand...
 




A

araines2750

Hexa Crazy
Jakjock
Can you please provide a more detailed explaination of how it went down.
Did it wobble violently, roll to left or right..., motor sounds..speed up or stop?
Can you provide photos of the aircraft before or after?
 


yakjock

yakjock

Member
araines2750 said:
Jakjock
Can you please provide a more detailed explaination of how it went down.
Did it wobble violently, roll to left or right..., motor sounds..speed up or stop?
Can you provide photos of the aircraft before or after?
Click to expand...
The craft was in a stable hover about 8-10 meters up in atti mode with a slight cross wind of about 3-4 mph about 20 seconds before the dive it wobbled very slightly but recovered. The copter then just pitched left & rotated about 90 degrees to the right & went down, the motor speed may have increase slightly but that may have also been me trying to recover the dive.
I dont have any before or after pics as i stripped it down when i got home & placed an order for a new frame from quadcopters uk. But there have been enough people who have posted pics of crashes on here to know what it looks like.


 

sim_io

sim_io

Member
really this is my interpretation of the beta update, v5.12a - fixed known bug where motors 7 & 8 had a countdown until automatic arm regardless of user input.
 

K

ksrimoungchanh

Member
the F550 only has 6 motors? can you help me understand the bug that would effect motors 7 & 8 on the F550? would that somehow mess with the 1-6 motors also?

KS
 

A

araines2750

Hexa Crazy
Jakjock,
Obviously I fly a very simlar set-up and am concerned about what happened to you.
With the 550 being a Hexa, I was under the current impression (maybe wrong) that the WKM has been updated to compensate for a motor/prop failure.
I have heard of S800 users loosing motors or props and landing to find one missing or not working.
With this asside, are all motor bullets tight to ESC?
I have also read of some ill effects from the stock DJI bullet connectors loosing connection as they are too loose in the ECS.
I have upgraded mine due to this.
I am assuming that this is not a new set-up and has been fully flown & tested.
I am suspicious of the radio/ interference.
Are you using a FPV downlink?
What kind of radio?
Have you flown at this location before?
I am not saying that the WKM is not at fault, but someting that has worked for numerous flight USUALLY does not just fail.
I STRONGLY suggest you contact your DJI dealer and request the WHM be checked by the factory.

I am sorry to hear about you crash, especially when a cause is not easily obtainable.
Please keep us (The Forum) informed on what you find out. Especially if it is a WHM issue and not a other hardware issue.
Good Luck!
 


K

ksrimoungchanh

Member
@ Kentjjl

did you see my video? no post mortem available.
craft had about 3 flights at that location.
1 RTH via TX power off successfully
1 good flight around park.. about 5-7 mins
this video as testing the LV alert landing. had been hovering for about a good 3 minutes already.. waiting for LV to kick off the landing.


We can eliminate pilot accidentally driving the craft down.. from this video.

Maybe that was the issue .. no pilot on stick.. WKM GPS mode.. hover in low alt to test LV landing procedure..

this video has about 3 minutes of just hover before this video.. so to save precious time, I cut it down to the action..

Needless to say, DJI and reseller, did a great job working and responding with me. No blames, just looking or post mortem. Ff I could find what I did wrong, it would be nice to avoid in future.

KS
 
Last edited by a moderator:

Droider

Droider

Drone Enthusiast
F550 WKM went down like a sack of bricks!!!
Click to expand...

Sounds like an esc/motor failure OR a loose or bad bullet connector. Gues the bullets ripped when the arms broke. The 20 second before twtci leads me to this conclusion.. Have u checked the battery? After the first flight did you check motor / esc temps?

Dave
 

Kilby

Kilby

Active Member
That sounds like you lost a motor/prop/esc. If it's a stock F550 kit from DJI, I'd look at the ESC's. Personally, i'm not a fan of them at all. The built in bullet connectors are a horrible design. I fly an F550, but I haven't had any problems. I use a WKM, but I don't use any other DJI parts. I have my own ESC's, motors and props.. never had a problem.

How long have you been running that firmware? If you saw some twitchy flight just prior, you could have seen the beginning of a ESC/Bullet failure.

Hope you find the problem. You should always try to find the cause of a problem after a crash before ripping the craft apart and ordering new parts.
 

K

ksrimoungchanh

Member
@ Kilby,

I agree.. I did send video and images of esc to reseller.. they quickly and promptly recalled my whole unit.. ARF and WKM.. and took it back. The even went as far as taking my TX/RX and test flight. I didn't get to do much, since both the reseller and DJI agreed to quickly look and take care of it.

But, I think Kilby is right on the mark... being able to document/record then analyze to find the root, gives room for more fun and flying time after wards.. and a wings and beer..:)

KS
 

DesJardins

DesJardins

Member
I have a question for those that have had a roll over...
What is everyones gain #'s?

I'm wondering if the gain values are too high causing extreme over correction. This is my first quad so I'd like to avoid another roll over in flight out of nowhere, hovering & forward flying
 


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