Request for tail servo trim parameter

Can we have a setup parameter to trim the tail servo so that the horn is at 90 degrees? Surely this would be a more logical way of getting good geometry than trying different servo horns and hoping for the best.

Hi,

you actually have it

Just check out the Autotrim panel: you can adjust each trim value manually (click and rotate).

Kind regards

Eddi

Born to fly ...
forced to work.

Wow, that's great! Was this added recently?

Hi,

no, has been there since the NEO and VBC are, you can even do it in the PC software (for other radio brands).

Kind regards

Eddi

Born to fly ...
forced to work.

Great, thanks

Setting up a new model and tried to use this parameter. As this is something you can tune in flight, the tail position isn't locked to the neutral position, so it's hard to know where to adjust it to. I don't know if the tail servo is in the neutral position unless I power up the heli and go straight to this menu without moving the heli or the rudder stick. I also need to be sure my collective stick is in the neutral position, otherwise it will add pre-comp to the tail servo. Even after doing this, when I go to to tail setup menu, the auto-trim value is not included in the tail neutral position and it goes back to being not at 90 degrees. It's hard to know if I've done it correctly, so I cleared everything and found a better servo horn.

Since on HH Gyros the center position is absolutely meaningless, i recommend another method:

Try to get about the same throw on both endpoints. So the best symmetry is, if the both endpoint values are the same, and you get the desired throw to both sides. You may add some degrees against the torque, but usually this dosent matter very much.

The Reason is, that there is a certain amount of attack that the tailblades can handle. This shall not exceed to any direction. Using same throw to both sides ensures about eqal stopping behaviour in both directions.

The Gyro will find its neede center position automatically, but it can use only the Range you allow with the endpoints. A Trimflight will do the fine tuning as usual.

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

Yes I'm sure the gyro will find it's center position automatically, but ideally I want my servo horn to be close to 90 degrees when in that position, otherwise the mechanical throw will not be symmetrical and I will need different endpoint values. I'm sure Vbar is excellent at compensating for mechanical dissymmetry but it shouldn't have to. Is there any reason not to have a trim adjustment for the tail servo? You have it for the swash plate servos.



Edited 1 time(s). Last edit at 04/11/2017 12:15AM by mahbouni.

The reason is simple:
It is not neded with a full Heading tail gyro. Just a relict from history -and sometimes yo have to drop such things ...

For main rotor it is needed due a different control algorithm.

regards (EN) / Gruss (DE)

Rainer Vetter

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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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There is conflicting information here. On the one hand, tail servo sub-trim to 90° is no longer necessary with full heading hold tail gyros. On the other hand, we are supposed to set up the tail center position so we end up with equal left and right travels. Add to that most helicopter manuals state to set the tail servo neutral position so that the arm makes a 90° angle with the tail rod.

You gave us the option to use sub-trim with the cyclic servos. All we ask is to give us the option to add sub-trim to the tail servo. There is no detriment to adding tail servo sub-trim. Whether or not tail servo sub-trim is necessary is questionable; let us decide.

Where is your real "tail neutral position"?

Consider there is none. Just a bench position which does not represent the neutral in hovering at your preferred headspeed.

The "real" hover "neutral" position is teached during trim flight, a bench value would always be off.

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.

Hi,

please check out the trim flight menu. You can adjust manually there.

Or just do the trim flight and let the VBar figure it out. This is like normal mode and trimming until there's no drift any more, just automated.

Kind regards

Eddi

Born to fly ...
forced to work.