NEO non v-link and BK 8002 servos

Greetings my friends,

I love my Vbar system (Control and 5 NEO's all are non V-link) but have what seems to be a compatibility issue with Bert Kammerer BK 8002 servos and the NEO satellite.

-The BK 8002 servos will work with a NEO V-link model
-The BK 8001 servos work fine with all of my NEO non V-link models
-The BK 8002 and 3001 servos freeze up with my all of my NEO non V-link models and the log shows Packets Lost message in my log files. The 8002 servos are really bad and the 3001 servos need a pitch pump setting above 30 to freeze up.

This does not appear to be a power issue. It was tested with external lipo battery power and internal BEC power.

Please see the videos...

BK 8002 servo freeze up

BK 3001 servo freeze up

Goblin 570 log files with BK 8002 servos

VBar Start -- Gobin 570 -- 21.06.2016 -- 16:52:14
16:52:15;1;Reset Reason: Power On
16:52:18;2;Calibration Finished
16:54:29;2;Bank 2 Loaded
16:54:33;2;Bank 3 Loaded
16:54:37;2;Bank 2 Loaded
16:54:38;2;Bank 1 Loaded
16:57:30;3;RC Input Packets lost
16:57:30;4;RC Failsafe activated
16:57:31;3;RC Input Packets lost
16:57:31;4;RC Failsafe activated
16:57:34;3;RC Input Packets lost
16:57:34;4;RC Failsafe activated
16:57:37;3;RC Input Packets lost
16:57:37;4;RC Failsafe activated
16:57:42;3;RC Input Packets lost
16:57:42;4;RC Failsafe activated
16:57:45;3;RC Input Packets lost
16:57:46;4;RC Failsafe activated
16:57:46;3;RC Input Packets lost
16:57:46;4;RC Failsafe activated
16:57:51;3;RC Input Packets lost
16:57:51;4;RC Failsafe activated
16:57:52;3;RC Input Packets lost
16:57:52;4;RC Failsafe activated
16:58:03;3;RC Input Packets lost
16:58:03;4;RC Failsafe activated
17:02:43;3;RC Input Packets lost
17:02:43;4;RC Failsafe activated
VBar Logfile End -- 21.06.2016 -- 17:04:36

It is a reverse voltage issue of this servos.

The VLink NEOS have a strong internal regulation - and the VLink is connected AFTER this item - so we can buffer bad servos here ;-)

The NON-VLINK - the Sat is connected here directly to the power bus where all the servos are connected too - so it gets all the spikes coming from the servos and could possibly shut off in case of worse servos disturbing other items more than needed.

I had this issue on the bench a while ago with this servos/Config - so i know it. Either ad a capacitor or use VLink or other servos.

regards (EN) / Gruss (DE)

Rainer Vetter

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1 mal bearbeitet. Zuletzt am 05.07.2016 23:23 von RV.

RV schrieb:
-------------------------------------------------------
> It is a reverse voltage issue of this servos.
>
> The VLink NEOS have a strong internal regulation -
> and the VLink is connected AFTER this item - so we
> can buffer bad servos here ;-)
>
> The NON-VLINK - the Sat is connected here directly
> to the power bus where all the servos are
> connected too - so it gets all the spikes coming
> from the servos and could possibly shut off in
> case of worse servos disturbing other items more
> than needed.
>
> I had this issue on the bench a while ago with
> this servos/Config - so i know it. Either ad a
> capacitor or use VLink or other servos.

It is easy to blame the servos. We all want to because we love Vbar. What I don't understand is that the flybarless system I took off my heli (iKon) has no problems with the servos. The Vbar NEO without v-link and using the satellite does. As I have shown in the video.

I'm not bashing either one because I like them both and it is hard to believe one model number different and they don't work. The designs have to be very similar.

This is why I chose not to bash the servos or the flybarless unit.

The other FBL's - the same reason - but might be not visible or not relevant, depending on the RX:

If you have a receiver directly connected to the servo powerbus (this is the key here) it can get into FS too. This depends a bit on the RX internal design (voltage regulation, how it is done, capacitors inside tec.) - but it still is a servo issue. A Receiver isn't supposed to treat such electric issues at all.

But - we show such a situation clearly in the logs, other RX may have a longer hold period and also don't have a log so you won't mention it. Throw a coin what might be better - showing up possible trouble in a log or just covering it ...

Believe me - i had exactly this issue on the bench here a few months ago and analyzed it. So - it is as it is - the servos are the culprit items here, just being on the edge to turn other components off for a brief moment. Using other servo types or serials (as you did in one heli with the non-Vlink) is the cross check for this thing.

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Posting and answering - please use a PC and a standard keyboard. Answer all questions fully, take the needed time, don't forget probably requested attachments.

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What size capacitor and where do I put it, power or signal?

Found this after some thinking....Ok im going to test an R2 Prototyping Super Capacitor Buffer Unit...... I herd about it for a different reason on heli nation. It is supposed to supply backup power but if it fixes this I'm going to have one on every heli. Good or bad servo im going to have one for safety after seeing the lockups.



1 mal bearbeitet. Zuletzt am 06.07.2016 06:49 von weracemo.

Hi,

we also don't want to bash either, we try and get to the bottom of things.
Here is more information (from some time ago, but still valid in the big picture): http://www.vstabi.info/en/node/1326

I would guess if we tested these particular servos, we would get the same results, and no matter what, voltages x times the nominal voltage of even 8.4 V have no place in the system, period. Some configurations might hide that, some not, but the problem is still there hidden under the surface.

I myself had BK servos of the 700x series at the oscilloscope, no issues, a few weeks later the same type but possibly a different batch, issues.

That's only facts, please don't get it wrong.

Kind regards

Eddi

Born to fly ...
forced to work.

About the Cap - as soon as i have added one single 16V 4700uF it was gone.

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Posting and answering - please use a PC and a standard keyboard. Answer all questions fully, take the needed time, don't forget probably requested attachments.

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RV schrieb:
-------------------------------------------------------
> About the Cap - as soon as i have added one single
> 16V 4700uF it was gone.


I found a Glitch Buster Power Capacitor for six bucks and it looks like I can pull the pins and put them in the two empty holes on the receiver so I won't be taking up another receiver port. Will this work?

Racers Edge 2472 Glitch Buster Power Capacitor

The two empty holes below the orange wire



1 mal bearbeitet. Zuletzt am 06.07.2016 21:56 von weracemo.

Yep - how much capacity does it have?

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Posting and answering - please use a PC and a standard keyboard. Answer all questions fully, take the needed time, don't forget probably requested attachments.

Für Posts und Antworten bitte einen PC und eine richtige Taststaur benutzen sowie alle Fragen vollständig abarbeiten. Nehmt Euch Zeit, beantwortet Rückfragen in Ruhe und vollständig.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
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I tested three types of capacitor systems, the first two were straight capacitors one was a Futaba buffer the other was a Racers Edge glitch buffer. Neither worked.

I tested the R2 Prototyping Buffer and it did not work as well.

Funny thing happened, when disconnecting the lipo from the hobbywing esc with bec and watching the R2 Prototyping Buffer drain down and having an Align tail servo plugged. The NEO satellite worked.

Unplug the Align tail servo and it stopped working

Plug in the lipo to the hobbywing it stopped working

Plug in a different lipo directly to the NEO and disconnect the Hobbywing and it did not work.

There is something in the circuit of the hobbywing esc while no powered on and in combination with the Align servo that allows the NEO external satellite to work... can this be an external frequency noise that is created and interfering with the antenna frequency?

Please see video...

new discovery with the compatability of the BK 8002 servos

HUUUHHH!!!!

Unbelievable! - Funny new experience - so the tail servo seem definitely a culprit item ;-(

Is it completely ok if you use another tail servo?

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Posting and answering - please use a PC and a standard keyboard. Answer all questions fully, take the needed time, don't forget probably requested attachments.

Für Posts und Antworten bitte einen PC und eine richtige Taststaur benutzen sowie alle Fragen vollständig abarbeiten. Nehmt Euch Zeit, beantwortet Rückfragen in Ruhe und vollständig.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Für Einzelkommunikation bitte ausschließlich Email verwenden! - PN, Messenger, Chat usw. werden nicht bearbeitet.
For single user communication please send a email only! PM, Messenger, Chat etc. won't be read.