Tail tuning on vbar 5.1 pro

Hi,

Newer with system Vbar 5.1 pro / FBL i've search on this forum before posting.

I've a logo 500 with 553mm main blade and 92mm raidx tail blade, a jive 100LV esc with a scorpion 4025-1100 motor.

I'm a little lost to tun my tail. It works very nicely but i want to fine tune it:

- if i give a full thottle/pitch : tail go to left, seems to be related to torque
- tail have a little wag (like little kick sometime) and maybe a very little drift
=> seems i've a little too high gain ?

Heres my vbar conf:
GYRO GAIN : 75
Advanced:
ACC:55
P GAIN : 78
I GAIN : 60
STOP gainA /B : 20
collective precomp : 22
cyclic precomp : 9
optimize uncheck

I don't know WHICH settings to adjust. Main gain ?

what's the symptom of too high/low p gain , i gain , stop A/B, collective precomp and cyclic precomp? Not see on manual.



thanks for answers ,

regards,

Hello croc,

please attach the current setup file

http://www.vstabi.info/en/node/822

and also a list of used servos, blades, headspeed.

Is it true that the tail boom goes to the left side?

Can you attach a image of the tail rotor in setup mode (sticks centered)?

regards (EN) / Gruss (DE)

Rainer Vetter

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Hello Rainer,

cyclics servos : Futaba BLS451
tail servo: Futaba BLS251
Headspeed: 1950 (idleup1)
Blade: edge 553mm fbl
AC blade: radix 92mm
weight : 3055g
lipo : 6S voltz 5100 35C

Like i say my configuration is very nice , it's just to have a perfect tail and understand setup (my first logo / vbar / fbl after some years with JR and hirobo).

Yes if i'm in hover and then push full throttle tail goes a little on the left then go back to middle (no drift)

if i do a 360° with tail in clockwise stop is not smooth (going back). On anti-clocksize it's ok.

thanks



Edited 1 time(s). Last edit at 07/06/2011 09:15PM by croc.

2 Things:

- With a BLS you should be able to run 90 gain.
- run the optimizer for one flight with a lot of tail piros and stops in both directions

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.

ok thanks, i'll try this two things next time and go here with some feedbacks. (in two weeks because i'm near to be in vacation without heli )

edit: i've never used optimise nor autotrims.



Edited 1 time(s). Last edit at 07/06/2011 09:45PM by croc.

Your RPM is pretty low also, try some 95MM edge tail blades (wider) and P/I to 75. Then adjust main tail gain to suit.

Back from vacation.

Thanks Rainer, I've rise up gain to 90 and use for one flight the tail optimizer and this do the job very nicely.

regards,

Im excited to read your results, cause I'm struggeling with some left drifting tail on full power climb out.
Misteriosly I can't seem to get a tailwag (BLS251) allthough I set the tail gain up to 100.

I've done six another flights this day. Tail is perfect for me and my level (acrobatic/soft 3D). (around 15mph wind). No drift or wag.

I've done some full power climb out and no problem any more after my optimization (gain is 90 now). Tail servo seems less hot than before (75 gain).

For information 51/30 with optimization. I think i'ts because i use full mechanical range on tail (maybe not a best practice as i've seen on vstabi wiki).

I do not want to hijack this thread but I have T-Rex 550 and Futaba 251s on tail. I have the gain set to 76, tail feels reasonably solid. I did not know that I could or should go as high as 90. I thought that the gain should be kept as low as possible just above the tail starting to wag. I am surprised to hear that the servo was hot at 75 gain and is colder at 90. I thought that the tail servo works generally much harder with higher gains than with lower. Am I wrong in here????

Well, I'd take such information with a pinch of salt as long as it's not a conclusion from a test series under certain conditions. No offense to croc, though, I do it the same way, touching the housing after a flight and taking a mental note.

In general, the overall gain can be set as high as possible until the tail starts oscillating (where I'd add: at a given rpm and at full airspeed at this rpm), then taken back say 5 points.

But that's harder on the hardware, of course, so I'm usually satisfied when the tail holds firmly and does "as being told", even if I could step up the gain 10 or 15 points without reaching the limit.

Cheers

Eddi

Born to fly ...
forced to work.

You are right Eddi, i share my experience only after having some problem to have a good tail and you should take it carefully because my conclusion may differ than yours

Maybe my tail servo is cooler only because i've no more some little tail wag and it's not related to gain , or flight condition. I've change two things at same time (gain & optimize mode), not the best way to know which of them correct my problems. I've no time to check that and so happy that it works than i don't want to change anything for now



Edited 3 time(s). Last edit at 07/30/2011 03:29PM by croc.

Well, 'happy' is all we want no matter what of both the changes did it.

Eddi

Born to fly ...
forced to work.