Problem with Naza lite = CRASH !

[i3dm]

Hello guys,

can anyone explain what might have happend here when the Naza Lite went crazy after going into failsafe?
http://www.youtube.com/watch?v=4rARAI0oxKU

it started spiralling, then stabilized and flew away, then spiralled again and crashed - all while being in RTH mode.

any ideas what might have happend here ?
i did test RTH in this machine many times before this flight.

 

[MultiCopterFPV]

I saw the video. When you recovered it, were all of the props still on? And was the speed controls still attached to the power distribution board? I had a similar crash a while back but it was a failure when one of the props came off. Looked just like your video. The Naza tried to compensate, but it spun out of control and crashed.

 

[i3dm]

all props were on, it didnt break a prop in flight.
this started much earlier upon entering fail safe, where it spiralled and then leveled off again - a quad could never level off if it lost a prop in flight.
it then spiralled again before finally crashing, but that was after a long almost level flight AWAY from home (in RTH mode) instead of TOWARDS home.

 

[stitch1615]

Compass calibration comes to mind.
Did you make any changes or add anything after you did the initial IMU and compass calibrations?

 

[olof]

In GPS or atti mode it should stop motors if tilted past 45º (I think it is about that).

So I would say that maybe the Naza came loose, tilted, or it is a HW failure. In manual mode it would behave like that. Is it possible you went into manual instead of failsafe?

 

[i3dm]

In GPS or atti mode it should stop motors if tilted past 45º (I think it is about that).

So I would say that maybe the Naza came loose, tilted, or it is a HW failure. In manual mode it would behave like that. Is it possible you went into manual instead of failsafe?

the only change is the presence of the FPV VTx (turned on) + Gopro.
should i do the compass calibration with these on ?

 

[i3dm]

In GPS or atti mode it should stop motors if tilted past 45º (I think it is about that).

So I would say that maybe the Naza came loose, tilted, or it is a HW failure. In manual mode it would behave like that. Is it possible you went into manual instead of failsafe?

1. motors neevr stopped.
2. controller was still glued 100% firmly to the frame after the crash (stock 3M tape is strong!)
3. im 100% sure that failsafe goes to RTH - it was tested many times with turning off the Tx or using the switch, and while it happend in flight, i also flicked the Tx switch to F/S just to be sure, then tried to turn off Tx and back on and regain control - nothing - the quad was out of radio range and as such, in F/S mode.

 

[Tahoe Ed]

It sounds like you were getting interference with your compass/gps from your vTx. What frequency are you using?

 

[i3dm]

im starting to think this might be a case of an extreme toilet bowl effect (TBE) ?

 

[i3dm]

1200Mhz.
this machine flew with this same setup many times (NO CHANGES) and always performed RTH 100% well.

 

[stitch1615]

the only change is the presence of the FPV VTx (turned on) + Gopro.
should i do the compass calibration with these on ?

Anytime you make any changes a safe bet is a fresh compass calibration.
RTH relys on the compass to properly work any electrics can affect it.
If the failsafe was not properly set in the Assistant, it could have gone into manual.
There are lots of variables but reconnecting to the assistant may tell you some reason.
After reinstall the smoke back into the ESC's, or wherever it came from,
reconnect to the assistant and see what it tells you.

 

[i3dm]

Anytime you make any changes a safe bet is a fresh compass calibration.
RTH relys on the compass to properly work any electrics can affect it.
If the failsafe was not properly set in the Assistant, it could have gone into manual.
There are lots of variables but reconnecting to the assistant may tell you some reason.
After reinstall the smoke back into the ESC's, or wherever it came from,
reconnect to the assistant and see what it tells you.

yes once the quad is back up (few days) i will test it on the assistant again but this is my 4th Naza and the setup was (as in all of my others) perfect - i have set up at least 10 Nazas over all - its not difficult.

 

[stitch1615]

yes once the quad is back up (few days) i will test it on the assistant again but this is my 4th Naza and the setup was (as in all of my others) perfect - i have set up at least 10 Nazas over all - its not difficult.

I recently returned my radio, a Spektrum DX8, to Horizon because for no reason my settings changed. I have no idea if it's the fault of the radio or something I did but it caused 2 near fatal (to the quad) errors to 2 different quads. I have been told that after any changes I should power up and down the radio to lock in the settings. I did and it happened again. I sent it back.
Not saying that is the issue but as simple as the programing has become, it is easy to make a mistake and not catch it. I now include a TX check in my pre-flight. I also take the time to put it on the assistant to check it out. It takes a few minuted but it takes a lot longer to do repairs.

 

[i3dm]

I recently returned my radio, a Spektrum DX8, to Horizon because for no reason my settings changed. I have no idea if it's the fault of the radio or something I did but it caused 2 near fatal (to the quad) errors to 2 different quads. I have been told that after any changes I should power up and down the radio to lock in the settings. I did and it happened again. I sent it back.
Not saying that is the issue but as simple as the programing has become, it is easy to make a mistake and not catch it. I now include a TX check in my pre-flight. I also take the time to put it on the assistant to check it out. It takes a few minuted but it takes a lot longer to do repairs.

Radio varified to be fine, thats not the case.
thanks for the tip though.