Naza acting weird. Crashed my 3500 dollar setup with naza gps today

A

akromatic

Member
I was going to do some night filming with my Vulcan 900 mm hexacopter today and I have the Naza with GPS on it. Tiger Motors 2814-10 with Xoar 12x5 props and 40 amp Dragonfly esc:s.
Powered by two Zippy flightmax 5800mAh 4s and a av200 gimbal underneath the frame with a nex-5n on it..
So what happened was that I started in GPS Atti mode and gained height to around 50 meters at 60-70% throttle. Then I just stood still in the air and started yawing to the right very slowly to pan around with the camera.. I´ve noticed before that when I yaw in either direction the hexa starts to drift and this happened this time too but I compensated the drifting carefully with the right stick.. Suddenly when I had yawed about 180 degrees to the right the Naza stops responding to stick input, the hexa tilts 20-30 degrees backwards and starts accelerating loosing height fast.. I panic and shut down the transmitter to get the Naza into failsafe but absolutely NOTHING happens and I KNOW my Failsafe is correctly set, and the hexa crashes into a spruce 5 meters from my neighbors house and got stuck between three branches at around 10 meters height.. I thought the hexa and all the gear was done for but after climbing the tree with the help of a ladder that my neighbor provided it turned out that two landing legs were bent and all the props had damages but everything else was fine, the camera continued to film (will post a movie of the crash and the moment when the Naza becomes uncontrollable later)..
I took the hexa back to my house, removed the props and started the motors and everything worked fine..
What the hell went wrong, I simply can't understand!???? I will definitely not trust that crappy Naza again, I won't fly the damn thing until I have a Wookong...
The only modification I have done to the Naza is to put black electric tape on the left side of the Naza becuse I was afraid to get problems with the barometer when the sun shines on the left side of the Naza (a common problem I've read)..
Does anyone have a clue why the Naza acted like this or have had a similar problem??? Could it be the recent assistant upgrade or something??
 

DesJardins

DesJardins

Member
Sorry to hear, sounds like a lock out... Kloner had this happen so maybe he can chime in as to what causes this to happen
 

R

RTRyder

Merlin of Multirotors
I doubt that its related to the assistant software upgrade. I've had similar problems over the last two weeks on three different quads with three different flight controller systems, the only thing in common was the outside temperature was right around freezing when it happened to each one. My conclusion is something in the electronics doesn't like cold weather, later in the day when things warmed up into the 40 degree F range I had no further problems with anything. For the remainder of the winter I'll be waiting until later in the day when things have warmed as much as they're going to before flying and also leave the multi outside on the ground for a while before a flight to let it cool to outside ambient temperature, maybe it will help, maybe not, but worth trying.

Ken
 

R

RTRyder

Merlin of Multirotors
DesJardins said:
Sorry to hear, sounds like a lock out... Kloner had this happen so maybe he can chime in as to what causes this to happen
Click to expand...


I've had lockouts, typically the quad just freezes in place provided the failsafe is correctly setup, I've never had one just take off on its own due to lockout. With the Naza and a lockout if you do nothing to regain the connection between TX and RX it will RTH with GPS or just land if there is no GPS connected.

Ken
 

02deuce

02deuce

Time Warped
How much weight are you running? From your description it sounds heavy which is why the Wookong M is recommended. I'm just starting to fly the Naza on a Disco and am having my own issues with it. I also fly an F550 with Wookong M and single way point and I can honestly say the Wookong M is TWICE as stable and solid in all three flying modes the n the NAZA.
 

DesJardins

DesJardins

Member
RTRyder said:
I've had lockouts, typically the quad just freezes in place provided the failsafe is correctly setup, I've never had one just take off on its own due to lockout. With the Naza and a lockout if you do nothing to regain the connection between TX and RX it will RTH with GPS or just land if there is no GPS connected.

Ken
Click to expand...
Well that's the reason I mentioned a video that Kloner has posted and I saw "lockout" mentioned with a tilt and went right into a bush since I don't have experience with this.

Also I know another person who had their MR dump multiple times when it was 40 degrees very early in the morning. They opened up their Naza and the foam inside was rock hard vs. the one that he had in the car which wasn't hard from being warm.

Might be worth questioning the cold weather stuff
 

A

akromatic

Member
Thank you guys for excellent input and ideas, I am starting to think it might be a temperature problem as several of you said. It was +5 degrees celcius at ground level when I flew and might have been colder 50 meters up. My auw was 4.9kgs so I don't know if weight has something to do with the weird behaviour but it has never been a problem before.
It makes me angry to know that Dji claims that Naza can fly in below zero celcius temperature.
Well, this was a lesson learned, no more flying during the winter.
Will definitely post the crashvideo later today when I figure out how to convert a video from a nex-5 to avi or mpeg and cut it down to reasonable size..
 

Droider

Droider

Drone Enthusiast
I would say GPS issues. It is always work checking for sunspot activity and satellite coverage before flying. I know this doesnot help now but practising flying without GPS and then with out Atti is a way you build your confidence NOT to hit RTH failsafe. If is is a satellite / sunspot issue hitting RTH aint going to help you.

As for the cold.. not sure about the Naza but I have flow my WKM in -35ºc no problem. I will be flying both in February in finland where I expect similar temperatures. Like RTryer has said it worth acclimatising you MR before flying especially when its come from a nice warm house in to the cold damp air.. but I would say it was GPS signal failure of some kind. The only other thing possibly is an ESC overheating under load.. I have had this but I managed to get her down in one piece.

At least your spruce tree saved it!

Dave

Couple of useful links

http://satpredictor.navcomtech.com

http://www.n3kl.org/sun/noaa.html
 


A

akromatic

Member
Droider said:
I would say GPS issues. It is always work checking for sunspot activity and satellite coverage before flying. I know this doesnot help now but practising flying without GPS and then with out Atti is a way you build your confidence NOT to hit RTH failsafe. If is is a satellite / sunspot issue hitting RTH aint going to help you.

As for the cold.. not sure about the Naza but I have flow my WKM in -35ºc no problem. I will be flying both in February in finland where I expect similar temperatures. Like RTryer has said it worth acclimatising you MR before flying especially when its come from a nice warm house in to the cold damp air.. but I would say it was GPS signal failure of some kind. The only other thing possibly is an ESC overheating under load.. I have had this but I managed to get her down in one piece.

At least your spruce tree saved it!

Dave

Couple of useful links

http://satpredictor.navcomtech.com

http://www.n3kl.org/sun/noaa.html
Click to expand...


Thanks for the input. Actually I almost always fly in atti-mode without GPS but now when I put on the gimbal I fly in gps-atti mode. I have done some manual flying too.
I simply panicked and should first have switched into atti-mode but went for failsafe instead...
 

Z

zooks

Member
I have heard that some people have problem with drift in the tx/rx so the setting of the switch between atti/gps was drifting and causing strange behavior.
 

nicwilke

nicwilke

Active Member
It would be interesting to know your C rating on your lipos. Also, what are your ESC's set up as? I had this same issue about 2 weeks ago, and found one ESC was set to shut off at higher voltage rather than soft at lower. Looks like the gimbal is showing a lot of vibration, that too can be effecting your sensors. I have a YS-X6 system and it gives me real time readings on this stuff, easier to diagnose.
Sorry for your crash.
 


C

Cameraj

Member
I had the same exact crash today, with naza on a 850mm hexa, I can't figure it out, at the end of a flight I was coming in tail first and all of a sudden it just took off and crashed in the hills
 

OneStopRC

OneStopRC

Dirty Little Hucker
Seemed to do it just as the wind picked up... Possible esc failure or maybe more likely the bullet connector failed?
 



TAPPEDOUT

TAPPEDOUT

Member
Would not use cheap receivers to transmitters. Should count the clicks and set dead center for modes just in case drifts point or two.it is a fairly narrow area it has to be set for mode selection.
 

D

DennyR

Active Member
I have some reservations about both Naza-M and H, mine have a very small hole drilled in the side of the case to allow some air to move in and out The idea that the case not being a totally sealed unit seems a bit hit and miss to me as far as venting goes. I think sun light could cause a pressure rise inside.
 

B

blushoes

Member
i have had similar experience with a WKM before. bought a AD8HL with Av200 all set up from a vendor. test flight (meaning 3 feet hover off the ground for 5 seconds) worked. so i parted with my cash.

next day, had a real test flight. hovering off 8m off the ground. doing nothin. just letting it hover.
i could clearly see one motor slow down in a split second. and craft started accelerating down in the direction of the failed arm.

post crash analysis - motor fine, esc fine. till now dont know waht caused it.

i was told 8 arms had more redundancy in case of failure. i know know (and have seen even hexas which DJI says can still fly with 1 arm down with latest FW)
in real life scenario, it really doesnt happen. i fly with parachutes now.
 

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