Hi guys.

I have just returned home after an unexplained uncontrolled crash.
I am running a skyjib 8 with ZTW 70A ESC and AXI 2826/12 motors, WKM v5.14 and duel wild scorpion 5s 5500mah.

I had two succesflu flights carrying the gimbal and camera this morning. About 30 secs into the third flight while i was hovering in Atti mode at about 2 metres the craft banked hard right, increased speed, tossed and turned like it was having a fit and then drove itself into the ground. My inputs had no effect that i could notice and i had no where near enough time to go manual. The LED gave no indication of any faults prior to it, and all props were intact and as far as i can tell spinning on impact.

It hit hard enough to bend the gimbal side frames and the gear rail mounting plate among many other items!

My gut feeling is that something happened with flight controller. I reconnected the batteries once the remnants of the props and other parts were removed and everything seems normal again. I really can't think of any other reason for this to happen.

i think i will be reverting back to a previous firmware for awhile.

Does anybody have any other thoughts on this incident? I hate to point the finger prematurely!

Thanks
Mike

I do not know if this is anything but I have a flat octo also and I noticed for the first time motors and esc's 7 and 8 are hot to the touch after I upgraded to 5.14a. I always check and touch things on landing and this never happened before. 2814 avaroto and 30 amp dji esc's. 12" gemfan
I reverted back to 5.12 better but still warm. I went back to 12a and all was good again.
got me man??????? I'm staying put for a while.

You've probably already checked, but have another look and see if your CoG has shifted.

Originally Posted by vip

I do not know if this is anything but I have a flat octo also and I noticed for the first time motors and esc's 7 and 8 are hot to the touch after I upgraded to 5.14a. I always check and touch things on landing and this never happened before. 2814 avaroto and 30 amp dji esc's. 12" gemfan
I reverted back to 5.13 better but still warm. I went back to 13a and all was good again.
got me man??????? I'm staying put for a while.

Originally Posted by Psionic001

You've probably already checked, but have another look and see if your CoG has shifted.

With my test experience, CoG changes should not cause extreme loss of control such as this. I'm still hung up on the idea that's it's counter productive to change Z axis values based on changes in payload weights. Here is my recent test video (fun video) to see how the WKM flew with and extreme change of CoG on the Z axis.

When Barbie is first hoisted there is absolutely no payload until her arms are straight and being pulled be the octo. So we go from zero weight on take off to ove 6 lbs. with a very low CoG

Flying Barbie (1 min 49 sec)

go on Barbie... go fly'

For me postition + alt-hold is the best so far with 5.14

Originally Posted by nicnaimless

With my test experience, CoG changes should not cause extreme loss of control such as this. I'm still hung up on the idea that's it's counter productive to change Z axis values based on changes in payload weights. Here is my recent test video (fun video) to see how the WKM flew with and extreme change of CoG on the Z axis.

When Barbie is first hoisted there is absolutely no payload until her arms are straight and being pulled be the octo. So we go from zero weight on take off to ove 6 lbs. with a very low CoG

http://youtu.be/oKj87qGsnOM

Not Again....lol

Check your ESCs for overheating. 3 of us in So Cal crashed our birds on 5.14a pretty much the same way last week and we believe the ESCs overheated. The shrink wrap burnt through on at least one of the ESCs. Talked to DJI China a few times and they said to try DJI ESCs. Know it wont work in your HL but that the response I got.

My crash was captured on video... see below. It happened during auto come home and land after about 5 mins of flying via GS. On decent to land, about 5' from ground, it twitched twice to the left and then motor 3 lost power, tilted and crashed. What's worst is because it was in failsafe mode, the motors WONT turn off (wont give me manual control) when toggling between GPS and Manual mode until failsafe is released (which I forgot to do) so my bird flip flop on the ground for a min before I was able to pull the power which did more damage than the actual crash!

My guess is 5.12 or 5.14a... there are changes to the firmware on how it controls the motors because I noticed motor 1 and 3 are always warmer than 2 and 4 but after 5.12 or 5.14a, it got HOT! DJI China said there were no changes to motor control in 5.12 or 5.14a though. So... not sure. Either revert back to pre 5.12 or try DJI ESCs I guess. I just got the DJI ESCs... will give that a try and see.

12 08 30 CX4 WKM 5 14a Crash SHORT (0 min 30 sec)

Ken

Originally Posted by MikeH320

Hi guys.

I have just returned home after an unexplained uncontrolled crash.
I am running a skyjib 8 with ZTW 70A ESC and AXI 2826/12 motors, WKM v5.14 and duel wild scorpion 5s 5500mah.

I had two succesflu flights carrying the gimbal and camera this morning. About 30 secs into the third flight while i was hovering in Atti mode at about 2 metres the craft banked hard right, increased speed, tossed and turned like it was having a fit and then drove itself into the ground. My inputs had no effect that i could notice and i had no where near enough time to go manual. The LED gave no indication of any faults prior to it, and all props were intact and as far as i can tell spinning on impact.

It hit hard enough to bend the gimbal side frames and the gear rail mounting plate among many other items!

My gut feeling is that something happened with flight controller. I reconnected the batteries once the remnants of the props and other parts were removed and everything seems normal again. I really can't think of any other reason for this to happen.

i think i will be reverting back to a previous firmware for awhile.

Does anybody have any other thoughts on this incident? I hate to point the finger prematurely!

Thanks
Mike

Originally Posted by Bengit

Not Again....lol

oh no...not again. Don't worry

Originally Posted by apeman88

Check your ESCs for overheating. 3 of us in So Cal crashed our birds on 5.14a pretty much the same way last week and we believe the ESCs overheated. The shrink wrap burnt through on at least one of the ESCs. Talked to DJI China a few times and they said to try DJI ESCs. Know it wont work in your HL but that the response I got.

My crash was captured on video... see below. It happened during auto come home and land after about 5 mins of flying via GS. On decent to land, about 5' from ground, it twitched twice to the left and then motor 3 lost power, tilted and crashed. What's worst is because it was in failsafe mode, the motors WONT turn off (wont give me manual control) when toggling between GPS and Manual mode until failsafe is released (which I forgot to do) so my bird flip flop on the ground for a min before I was able to pull the power which did more damage than the actual crash!

My guess is 5.12 or 5.14a... there are changes to the firmware on how it controls the motors because I noticed motor 1 and 3 are always warmer than 2 and 4 but after 5.12 or 5.14a, it got HOT! DJI China said there were no changes to motor control in 5.12 or 5.14a though. So... not sure. Either revert back to pre 5.12 or try DJI ESCs I guess. I just got the DJI ESCs... will give that a try and see.

http://www.youtube.com/watch?v=jhCraEwUkpA

Ken

That's one of the worse sounds I ever heard coming out of a multirotor. Sorry for your loss Ken. At least you have a video so now DJI or your dealer should replce the broken parts.
For the mean time I am staying put. No flying since Canada day (july 1st) when mine took a dive.

Cheers

Funny you should mention that... and just confirmed with the DJI ESC... the high pitch whine is gone. The Maytech V1 was making the motors whine... which I'm glad to get rid of!

Ken

Originally Posted by bcollydas

That's one of the worse sounds I ever heard coming out of a multirotor. Sorry for your loss Ken. At least you have a video so now DJI or your dealer should replce the broken parts.
For the mean time I am staying put. No flying since Canada day (july 1st) when mine took a dive.

Cheers

Here's a pic of the Maytech 35A V1 ESC that got overheated and broke through the shrinkwrap.


Ken

My ESC's appear to be fine Although it all happened so fast i will admit tht i never thought to check them. Considering i had already had two five minute flights then a break of about 3 hrs before the third flight of 30 sec I doubt it was the ESC's overheating.
I have spoken with my DJI rep and he has forwarded my incident onto DJI, preliminary thoughts is an IMU issue so we will see.

Originally Posted by MikeH320

My ESC's appear to be fine Although it all happened so fast i will admit tht i never thought to check them. Considering i had already had two five minute flights then a break of about 3 hrs before the third flight of 30 sec I doubt it was the ESC's overheating.
I have spoken with my DJI rep and he has forwarded my incident onto DJI, preliminary thoughts is an IMU issue so we will see.

Camera on board? Video? I never fly without video. Made for a fun video when I lost a prop!

it was on board but not recording! I was just doing a quick test on the gimbal after a minor modification, the mod worked but not the big bird