YS 120 with V-Bar Gov not working properly

Hello,
I have problems with the governor (Nitro 2 channel mode) of the V-Bar on Trex700 Nitro.
I get a huge drop in head speed when I unload the rotor. It 's impossible to do 3D in this way!
If I make a vertical climb to full pitch (20-30 meters) and then put quickly to zero pitch , the engine seems turn off and after a moment resumed RPM
Before using the govenr of V-Bar I used another governr and I never had this problem (engine, fuel ,tuning, sensor, etc are always the same). I also tried to reinstall the old governor and all works fine.
What do to fix it?
Regard
Tb77

This sounds like a by far too steep throttle curve. Please post the complete vbar setup and the throttle curve of your transmitter.

What i heard, is that specially this motor has a very steep resonance, so it has a very stiff natural rpm behaviour. Did you try flying it with the curve only to verify its at least nearly correct?

so long ... Uli
http://www.vstabi.de

ulrich Wrote:
-------------------------------------------------------
> This sounds like a by far too steep throttle
> curve. Please post the complete vbar setup and the
> throttle curve of your transmitter.
>
> What i heard, is that specially this motor has a
> very steep resonance, so it has a very stiff
> natural rpm behaviour. Did you try flying it with
> the curve only to verify its at least nearly
> correct?

Thanks for respons, just returning at home I attach the setup of vbar. I have not tried only with the curve of Tx but I tried with another engine (os91) and the problem is the same.



Edited 1 time(s). Last edit at 07/16/2012 05:15PM by gguadagno77.

ulrich Wrote:
-------------------------------------------------------
> This sounds like a by far too steep throttle
> curve. Please post the complete vbar setup and the
> throttle curve of your transmitter.
>
> What i heard, is that specially this motor has a
> very steep resonance, so it has a very stiff
> natural rpm behaviour. Did you try flying it with
> the curve only to verify its at least nearly
> correct?

Hello,
in attached you can find my setup, the throttle curve are:
Normal (non governor actived): -100,0,+100
Inde1 and Idle 2 (governor on): +100,+80,+100

I hope that you can help me....I'm very disappointed
Bye
Giovanni

Hello Giovanni,

first we have to seperate if there is a problem with the governor and its settings (which i can't see at the moment) or the motor, muffler etc. itself.

Therefore please turn off the Vbar gov by keeping the RPM preset channel at -100% and fly the heli with the throttle curve from TX only. If it is still there try to modify the curve, more flat, e.g. 100-90-90 and check again.

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
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RV Wrote:
-------------------------------------------------------
> Hello Giovanni,
>
> first we have to seperate if there is a problem
> with the governor and its settings (which i can't
> see at the moment) or the motor, muffler etc.
> itself.
>
> Therefore please turn off the Vbar gov by keeping
> the RPM preset channel at -100% and fly the heli
> with the throttle curve from TX only. If it is
> still there try to modify the curve, more flat,
> e.g. 100-90-90 and check again.


Hello Rainer,
Thanks for your interest.

I do not think this is a "mechanical" problem, before using the govenr of V-Bar I used another governr and I never had this problem (engine, fuel, tuning, sensor, etc. are always the same). Also I tried to reinstall the old governor and all works fine.

Regarding TX throttle curve curves I followed this concept:
More the "V" of the curve is steep, more the V-bar governor is aggressive (ex.: +100,+50,+100 is more aggressive that +100,+80,+100) is right?
Thanks
Giovanni

Quote:

please turn off the Vbar gov by keeping the RPM preset channel at -100% and fly the heli with the throttle curve from TX only. If it is still there try to modify the curve, more flat, e.g. 100-90-90 and check again.

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.

RV Wrote:
-------------------------------------------------------
> please turn off the Vbar gov by keeping the RPM
> preset channel at -100% and fly the heli with the
> throttle curve from TX only. If it is still there
> try to modify the curve, more flat, e.g. 100-90-90
> and check again.


I will follow your advice and let you know.
Many thanks
Giovanni

RV Wrote:
-------------------------------------------------------
> please turn off the Vbar gov by keeping the RPM
> preset channel at -100% and fly the heli with the
> throttle curve from TX only. If it is still there
> try to modify the curve, more flat, e.g. 100-90-90
> and check again.


Hello,
Today I did the tests you suggested:
Turn off gov and fly only with TX curves...engine works fine
Then I reactivated the governor and I did the throttle curve on TX 100,90,90 (as you suggested) and reduced the gain to 37 .... with standard gain I have problems with the maximum (like how you hold the throttle of motorbike up and activate the RPM limiter) the probmea is much improved but not disappeared. What other parameters can I change?
In my opinion the V-bar in a condition of high overspeeding (ex.: when you download the rotor after a fast vertical climbing ) reduce the throttle and then re-open the throttle to much quickly, causing a short suffocation of the engine.
In fact, if you tune engine a very lean the problem disappear but the engine becomes too hot.
What do you think?
Regards
Giovanni

Try playing with the collective dynamic parameter. Set it to 0 first to check if it improves. Then the differential may have influence too.

Set both parameters to 0 and check how it goes. Both parameters are useful to have a better response on slow reacting nitros. The default values are tuned for a OS90 in a 700 nitro. There they work perfect. But the throttle curve we used on the setup is 100-30-0-30-100 or in the classic notation 100-65-50-65-100 , so its much steeper. This may have to do with the muffler used. It was a non resonating one. Its quite strange, that your very flat throttle curve works so far. The Throttle is barely moved on the whole pitch range...

so long ... Uli
http://www.vstabi.de

ulrich Wrote:
-------------------------------------------------------
> Try playing with the collective dynamic parameter.
> Set it to 0 first to check if it improves. Then
> the differential may have influence too.
>
> Set both parameters to 0 and check how it goes.
> Both parameters are useful to have a better
> response on slow reacting nitros. The default
> values are tuned for a OS90 in a 700 nitro. There
> they work perfect. But the throttle curve we used
> on the setup is 100-30-0-30-100 or in the classic
> notation 100-65-50-65-100 , so its much steeper.
> This may have to do with the muffler used. It was
> a non resonating one. Its quite strange, that your
> very flat throttle curve works so far. The
> Throttle is barely moved on the whole pitch
> range...


Hello,
Many thanks for your reply.

I've also tried setting the curves of TX as the standard V-bar but the defect was very pronounced.

Just to goats better:
- More the "V" of the trhottle curve is steep, more the governor is aggressive (more faster the response of throttle) (ex.: +100,+50,+100 is more aggressive that +100,+80,+100) is right?
- Can I make a flat curve (ex: 90,90,90)?
- Could you explain the principle on which they are based parameters "collective dinamic" and "differential" (ex: Zero = slow response - 100 = fast response)

Many people with this engine using the attached parameters, what do you think? Have a logic with the reported problem?

Thanks in advance for the answer
Kind regards
Giovanni

ulrich Wrote:
-------------------------------------------------------
> Try playing with the collective dynamic parameter.
> Set it to 0 first to check if it improves. Then
> the differential may have influence too.
>
> Set both parameters to 0 and check how it goes.
> Both parameters are useful to have a better
> response on slow reacting nitros. The default
> values are tuned for a OS90 in a 700 nitro. There
> they work perfect. But the throttle curve we used
> on the setup is 100-30-0-30-100 or in the classic
> notation 100-65-50-65-100 , so its much steeper.
> This may have to do with the muffler used. It was
> a non resonating one. Its quite strange, that your
> very flat throttle curve works so far. The
> Throttle is barely moved on the whole pitch
> range...


Hello,
I tried to follow your advice and engine was better but the problem did not disappear completely.
To make a definitive comparison I installed even another governor ( To test the two configurations was enough to change the program on the TX and plug in the sensor and the throttle servo on control units.) without changing anything, mechanical or carburetion.
The result was that the another governor works better (without any kind of problem) than V-bar governor. I'm not saying it's better but you get excellent results without becoming crazy.
I think the V-bar gov for Nitros must be improved. There are many users who write on forums that they have problems with Vbar nitro gov
For now I will continue to fly with another governor, but I hope that this matter will be solved asap
Thank you very much for the help you have been very kind.
Bye
Giovanni

Hi

I confirm same problems on two YS120 what i tried on VStabi governor. I was able to reduce this strange behaviour, but i was not able to eliminate it and get satisfactory results. Both motors run good on curves without governor. I got best results with almost flat curve and collective dynamic set to 0 in VStabi governor, may be that it is needed to change other settings. Uli, it is possible that you will get YS120 and try to tweak VStabi governor settings on this motor and post your result here?

Well, i am a full non Nitro Guy We did testing on a OS 90 which went quite well like expected.

There is nothing wrong in using it with an almost flat throttle curve an very low gain. Thats what we use on electrics...

It seems that the motor has some sort of inherent speed control, probably because of it construction. So its extremly different to the normal nitor behaviour.

Is someone of you at IRCHA? This may be a nice opportunity to check and try some things.

so long ... Uli
http://www.vstabi.de

I am a full electric guy too. Almost flat curve and collective dynamic 0 is not enough to get satisfactory result. I am already tired from tweaking YS120 on VStabi governor. Both motors now fly on curves. IRCHA ... no. I think that this theme is actual because YS120 seems to be popular.

Hello,
I'm sorry but IRCHA is too far from me

swalko Wrote:
-------------------------------------------------------
> I am a full electric guy too. Almost flat curve
> and collective dynamic 0 is not enough to get
> satisfactory result. I am already tired from
> tweaking YS120 on VStabi governor. Both motors now
> fly on curves. IRCHA ... no. I think that this
> theme is actual because YS120 seems to be popular.[color=#FF0000][/color]

quote

Anyone at IRCHA with a VBAR+YS120, shoud be no problem if its really popular. I am not very often in the USA...

so long ... Uli
http://www.vstabi.de

What a good idea this is - I am looking to swapping my YS91SR to a YS120 soon and this would be so useful before I do the change.

Hope someone going to IRCHA can oblige

I am having this same issue with YS60SR in my N5c using vbar silverline (latest firmware) and futaba GV1 sensor. Has there been any definitive solution identified yet (I am yet to try the above suggestions and currently have stock vbar governor curves and settings in nitro combined mode using my JR XG8 with standard receiver hookup)?

I am using a Futaba s9257 for the throttle servo. Could it be that a this servo (normally a tail servo in 450 helis) is too fast?

Also what do the vbar throttle curves do in governor mode? (I don't understand their purpose when the headspeed is being governed - excuse my ignorance)

Psych101 Wrote:
-------------------------------------------------------
> I am having this same issue with YS60SR in my N5c
> using vbar silverline (latest firmware) and futaba
> GV1 sensor. Has there been any definitive
> solution identified yet (I am yet to try the above
> suggestions and currently have stock vbar governor
> curves and settings in nitro combined mode using
> my JR XG8 with standard receiver hookup)?
>
> I am using a Futaba s9257 for the throttle servo.
> Could it be that a this servo (normally a tail
> servo in 450 helis) is too fast?
>
> Also what do the vbar throttle curves do in
> governor mode? (I don't understand their purpose
> when the headspeed is being governed - excuse my
> ignorance)

For those interested I solved my problem today by adjusting the 'minimum gov' setting. First I tried only conservative adjustments up from the stock -50 setting all the way up to 0 but this did not get rid of the problem. I was still not overspeeding in any noticeable way so I tried an extreme value of +30 to see if this would make any noticeable difference. This value fixed the problem completely. I was overspeeding a bit with this setting so I can probably drop it back down a bit but there is no more engine hesitation and the gov is working really well.

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.

saludos................
toda la gente del foro vbar...............
un concejo:
el motor debe de estar bien entonado................dependiendo de su localidad o sitio de vuelo, observen y prueben en tipo de bujía (enya 3, 4, 5), lo otro que deberían observar y sentir son los cambios aplicados en el software de nitro avanzado...... deberían de ir ajustando cada parámetro y ver el comportamiento de motor e cuanto a maniobras exigentes..........
yo volé un velocity 90 con ys120 y el software 5.2, y de verdad que el gobernador es excelente yo no tuve problemas ni siquiera con el mínimo (ralenti)..........
saludos.......................

Quote:

Translate:
Greetings ................ everyone in the VBar forum ............... a tip: the engine should be well toned ................ depending on your location or flying site, observe and try to plug type (enya 3, 4, 5) , the other thing you should check and try out are changes that can be made in nitro advanced software ...... should go adjusting each parameter and see the motor behavior and demanding maneuvers about .......... I flew one ys120 velocity and 90 with software 5.2, and truth that the governor is excellent I had no problems even with the minimum (idle) .......... greetings .......................

Cheers

Eddi

Born to fly ...
forced to work.