Logo 600 crash from no control/power after 2 minutes of flight

Ok, so my 600 went down with no control/response from the V-control.

It's been 60+ flights since last crash.

This seemed to happen once or twice a few years ago but not since (and was a blue line VBar back then). It is now a NEO with Pro/rescue.

I was coming back from a far distance & altitude, into a 30+MPH wind and a gust came pushing it further away. I tried fighting it and before I could even hit rescue, I lost power and the HeliJive didn't seem to even go into failsafe so I just hit TH from about 20' up.

I'm posting the log to see if any of you have an idea what happened. Peak amps was 120.3 on a HeliJive 120 and since it's peak limit is appx 240A, it shouldn't have played into this. Also, the log says I hit Bailout but there was no end at 14:23:07 Then it says I hit it again and I oversteered to end it but I don't think I did. If I did hit Bailout again, it wasn't working. BTW, I do test bailout at least once almost every flight.

Grounding kit is installed with continuity from tail shaft to motor mount.

14:21:46;2;Raised Vibration Level
14:21:56;3;High Vibration Level
14:22:06;3;High Vibration Level
14:22:16;3;High Vibration Level
14:22:26;2;Raised Vibration Level
14:22:36;2;Raised Vibration Level
14:22:47;2;Raised Vibration Level
14:22:56;3;High Vibration Level
14:23:03;3;The Cyclic Ring is active
14:23:03;3;The Cyclic Ring is active
14:23:03;3;The Cyclic Ring is active
14:23:07;3;High Vibration Level
14:23:07;2;Bailout Start
14:23:07;3;The Cyclic Ring is active
14:23:08;4;Aileron Sensor Value out of Range
14:23:08;2;Bailout Start
14:23:11;3;The Cyclic Ring is active
14:23:11;3;RC Input Packets lost
14:23:12;2;Bailout End
14:23:12;2;Bailout Pilot Oversteer
14:23:12;1;Motorswitch Motor Off
14:23:16;3;RC Input Packets lost
14:23:16;4;RC Failsafe activated
14:23:21;3;RC Input Packets lost
14:23:31;3;RC Input Packets lost
14:24:30;3;RC Input Packets lost
14:24:33;3;RC Input Packets lost
VBar Logfile End -- 29.05.2017 -- 14:24:48


Thanks.

Dave



Edited 1 time(s). Last edit at 05/31/2017 03:40PM by 3D Dave.

Hi Dave,

please take a screenshot of the Antenna Status display while the VBar NEO from your Logo 600 has connection.

Looking forward to your answer ;-)

Alex, I did a quick power up to check the antenna status but I did not see anything out of the ordinary.

I can do it again and take a screenshot this time if you think something important is there.

Are you wanting me to do this with the TX and heli separated (ie range check) or is this something that will show up just by powering on both, connected and just looking at the screen?

One thing I did notice when double-checking for ground continuity, it is intermittent if I touch my DVM meter probe (other end touching the motor mount) to the outer wall of the tensioner bearing.

I wonder if that was enough to cause enough of a static build up and then NEO malfunction?

If I touch the inside race of the bearing, I get continuity. I think I should change my whole tensioner bearing/CF tube pieces/bolt & nut (Mikado supplied) but I'm not sure what would replace it (that would work better)???



Edited 1 time(s). Last edit at 06/01/2017 06:05AM by 3D Dave.

One guess ...

If the motor was still running and the rescue does not seem to help it could be a mechanical issue.

There are some CR entries a few seconds before rescue was hit. But - thise entries are not normal for your flying at this point described above.

So it might be possible that something mechanical (ball link etc.) failed - the control loop gave full trow on swash until the CR limits (and sets entries in log) but with no effect on the model. This is where you may feel "no power" - i had this with a broken ball link from swash to one blade a few years ago.

I think all entries later regarding packets etc. have been on the ground which is normal.

regards (EN) / Gruss (DE)

Rainer Vetter

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Thanks Rainer.

That could be the case, but I guess there's no way to know for sure.

That said, what exactly are you (and most guys) doing to complete the ground path from the wire opposite the eyelet screwed into the boom to the bearing? Something custom?

My original SE had 1 standard bearing and 4 CF spacer tubes. Is there something better than that, or the new, larger bearing and 2 spacer tubes that come in the current kit #04273 (http://www.mikadousa.com/Tailrotor_c_147.html)?

I just bought the Spedix metal tail belt wheel tensioner bearing kit but in checking continuity, the electrical path is not complete from the sides to the outer sleeve of the bearing. This is no better electrically than my original kit.

Thanks for your help.



Edited 2 time(s). Last edit at 06/06/2017 03:00AM by 3D Dave.

Hi,

although there is no proper continuity (high impedance) between all the parts and pieces, if the anti static kit is in place as recommended, it works with all the tail rotor varieties we had in the past. If you measure continuity between the eyelets or the screw/motor mount respectively, all is well. Transfer resistance is low enough even if there seems to be no continuity, all the time, between all the parts.

On the other hand, some people favor anti static spray, either as a substitute or additionally. Problem is, you have to re-apply the spray every so often.
So if I would consider this, I would still leave the wire in place, just for good measure.

Kind regards

Eddi

Born to fly ...
forced to work.

Hi Eddi.

Thanks for the input. The only thing is, this is not the first time for this to happen.

I had it happen a few times when I first built it (was an SE) in spring 2012 and then at least 2-3 more times between then and now.

I've always had the stock ground kit on the tail (and even had a little better conductivity with the original bearing).

I sometimes wonder if there is something about how the HeliJive plays with the Xera 4035/3Y-400 but could never pin-point the problem to something else besides static.

Since I've been dealing with this for 5 years now, After the next crash, I might just give up on the entire heli, motor and HeliJive.

I had well over 400 flights on it as an SE and now almost 60 as a standard 600 size.

Funny, I have well over 1000 flights on my 500 and never had an issue like this.

If you have any other suggestions at all, I'm all ears.

Sincerely,

Dave



Edited 2 time(s). Last edit at 06/07/2017 02:16AM by 3D Dave.

Being out far with a wind....could you hear the heli Dave? ie: do you know if the motor was running under power or not? If you can't confirm you had main power, the loss of control could have been from lack of main rotor rpm. Been there....done that.
The increase in vibration and cyclic ring limit warnings also occur as the rotor head spools down and no longer has the control force to move the heli as the NEO is trying to do in response to the pilot's inputs.

This could be another example case of why I was requesting the Low Rotor RPM Warning feature for the VControl ( Feature request - low RPM alarm )...... so the pilot knows as soon as loss of motor power occurs...even if they can't hear the heli. So they can put the heli into a controlled auto-rotation before loss of cyclic control and the resulting crash.

KevinB



Edited 1 time(s). Last edit at 06/09/2017 06:52AM by KevinB.

Thanks Kevin.

Yes, it was very windy and the heli was at least 50 yards away and 20 feet high.

I suppose the motor RPM could have dropped.

If it was lack of rotor RPM, I'd like to confirm what caused it, and why.

I'm running a NEO now but previously (during the previous 3-4 crashes with the exact same loss of control) it had a blue, full size V-Bar. The only other difference for the last 60 flights is I changed from V-Bar gov. (because of the hard start up swinging the heli) to the HeliJive gov.

Hi,

I'm afraid ESCs cutting out is not uncommon. If you are lucky (and notice it soon enough, and the model is still powered) you can see the LED flashing a code. If you power down, or if the battery gets disconnected, the tell tale is gone. Sometimes, ESCs don't even blink a code, maybe if they just did reset (for whatever reason).

As Kevin states, the log file entries could be evidence.

I'm not sure if HeliJive ESCs have an event and/or fault recorder, if you or K could read the cause from the ESC, or if not the cause, at least that it did stop.

With the Jive Pro or Kosmiks, I suppose you could read it from the ESC's log.

And it's at least possible that the internal governor does different things, maybe draws higher peak amps, than the external governor, and of course the software/processing is different than if the ESC is more or less only running as a throttle servo, also the safety features (shut down because of temperature, peak load, whatever) _could_ be different.

And then, I'm not sure about the Xera motor. Are these very high-bred motors, like re-wound Kontronik or Scorpion motors? There have been issues reported with such, commutation errors could probably lead to cut-outs, this is why—to the best of my knowledge—the KSA mode was implemented, which can help if you have issues with 'large can' motors.

It's difficult to pinpoint the cause, but at least from the event log we can pretty much rule out a radio link issue. We can see it is logged (as a proof and reference), but only after the impact, so we can pretty much assume that it would have been logged if it had been there earlier on.
After the impact, on the ground, such entries are not uncommon, 2.4 GHz has hardly any range any more, directly on the ground. A couple of inches away from the ground increase the range considerably, and in the air we have what we have.
Bailout has been triggered and logged, but only one second before the impact or so it seems, and a second time, at the time of the impact.
From what you experienced, and from the log file entries, if the model did not react to control inputs or bailout (if not in time, but it should have), and with the cyclic ring entries, it looks like the VBar had no leverage any more.
This could mean either a mechanical or servo issue, or a power loss gone unnoticed until too late.
I wonder if there are any or unusually many cyclic ring entries in earlier logs. If not, I would assume that the model is set up in a way so you hardly ever reach the ring limits, then the entries here would be unusual, obviously, and could even more be evidence for something not in order.

Kind regards

Eddi

Born to fly ...
forced to work.

Hi Eddi.

I know the Jives flash a code but immediately after a crash, my first priority is to unplug the battery so I don't burn anything up. In addition, my Jive is mounted heatsink up which means the LED light is on the bottom so I can't see it without removing the ESC. Since it's mounted with servo tape, it would take too long to get it off to see the code.

I'm almost positive the HeliJive does not have a fault recorder.

The motor is a stock Xera 4035/3y-400 purchased new in 2011 and has never been rewound.

I don't recall anyone needing to run KSA mode with that motor, but I guess it might be possible.

Servos are Futaba BLS 251 and 451's

Yes, the model is set up per the manual and I don't recall seeing cyclic ring entries previously, but I wasn't looking at many logs after building it.

Like you said, it's difficult to pinpoint the cause and since I can't figure it out, I'll likely get rid of the motor and ESC and try a different combination.

I could send the ESC to Kontronik, but since Jives are sealed in plastic, I don't think they can do anything with it besides test it.


Just out of curiosity, what ESCs and motors do you run together?