As the title says I have some serious problems when in full left or right rudder the pirouette is very slow and in a high speed pass the tail shutters ( SHAKES REAL FAST BACK AND FORTH ) as if tail gain is to high
my set up is as follows
1- cc160 esc
2- 850mx 490 kv motor
3- spirit pro
4- 690 mains
5- 115 tail
6- 25 tooth pinion
7- 214 for main
8- tail 26 tooth
9- gyro 45
10-rudder common gain 1.30
11- pirouette consistency 185
12- rotation speed rudder 12
all other settings are default
I'm not happy I'm a Beastx guy and I also set up a 420 and 500 Goblin and they fly flawless.
I it possible the tail blades are not long enough

Hi,

very likely the problem will be in the Rudder Delay if it is at default.
Please check this page with recommended value for your servo:
http://manual.spirit-system.com/index.p ... Servo_list

If you can attach all your settings (4ds file) then I can check it all.
Tail Gain is quite low, but it could be also caused because of too high Rudder Delay.

If tail is slow, then I guess that Rudder End-points are not configured properly. With Rotation Speed at 12 it should be quite fast.

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Spirit System developer

Hello Tomas,

Here is the profile file in .4ds as requested.

Morris

Thank you for the settings.

I have found that the Pirouette Consistency is set to 160 which is not enough for this helicopter.
I dont know what is your servo, but for sure it should be at least 175.
If it is Futaba BLS servo, then you might need to set 190, but not more.
Could you also reveal what servos you have so I can help you more, please?

Normal tail gain for this helicopter should be around 60%. When you decrease Gyro Gain is the oscillation issue solved? Does the tail still hold with decrease gain?
If no then I guess the problem will be in the mechanics.

Is the kit very new or it was verified to work well previously? New kits might require some tweaking to make the mechanics smooth (especially push rods).

_________________
Spirit System developer

The kit is brand new first time up in the air I'm using BK BLS-8005HV servos, from my original post with values I have changed them to the file that I sent .I just got back from 2 flights and no change fast forward flight the tail goes nuts gyro in TX is set to 30 . The tail piro is still very slow in flight . I will redo all endpoints . I am a Beastx guy and can set them up blindfolded . I built a goblin 420 and 500 the same time I built this 700 and the other 2 have Beastx in them and they fly amazing with almost zero tuning in the field.

Hello,

thank you very much!

For this servo you can set Pirouette Consistency to 185 and Rudder Delay to 0.
Next thing, please check how the mechanical center for the tail is configured.
When you enable Servos/Subtrim (tuning) all the servo arms should move exactly to the center position (including rudder servo arm).
At the same time there should be a slight angle between tail blades so that there are 3-4° (roughly).

Other than that it should work out of the box with Goblin preset. So if above will not help, I fear the problem will be in the mechanics.
Unfortunately there are big differences between kits. I am helping people for several years so we have found all the problems that people were suffering with models, including SAB.
Unfortunately some kits are coming with very tight ball linkages which is not good - please check that there is absolutely no friction so that rudder push rod is moving completely freely.

The best way to check the mechanics is to remove all blades, then disconnect push rod from rudder servo arm and start the motor to your flight RPM.
Then carefully move by hand with the push rod in the whole range and check how smooth it is going. If there are no revolutions, then mechanics can work very well. But under load mechanics can work very differently. This is happening when for example axial bearings are not fitted in the right direction or there is some asymmetry.

Yes, with Spirit it should work similarly as with Microbeast, very likely tuning can be even faster since we have preset for Goblin.

If you will find nothing, please verify also the rudder servo - for example just try to touch by finger the servo case while motor is spinning and observe the servo arm. Unfortunately we have relatively frequent reports from pilots that they are finding BK servos to not work correctly. Usually the problems are occuring as soon as the motor is running as some are more sensitive for noise. This results in a random jittering (whatever Gyro Gain you have) - so in the flight you will see usually oscillations. There I can give you also few suggestions what to check particularly with the servo. In some we have found that wires were partially shorted by aluminium case in the rubber grommet. But this was happening mostly with BK-700X servos.
I am mentioning this just in case, because there might be everything else OK and whatever you will set in the unit, it will not help.

On the other hand, these servos are rated with very good specs. So normally it should work exceptionally well as these servos have very good performance. But even with two times slower, there should be no oscillation.

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Spirit System developer

I have owned several BK servos (micro, mini, and standard size, cyclic and rudder, coreless and brushless). All of the BK servos have worked very well with the Spirit units except for two BK BLS-8005HV rudder servos I tried. I sold both of those BK BLS-8005HV to folks who use other FBL units, and both guys claimed the servo worked very well for them.

Yes, we know about several cases when the servo behaved correctly on a different helicopter, regardless used unit. It is dependent on a frame, servo mounting and wiring, BEC voltage, ESC, used motor - whatever that can carry or generate noise.
In some cases using for example 4x BK resulted in bad behavior of 2 of them. Disconnecting one made the rest working correctly.
The problems are occuring also with just a receiver. The servos are equipped with high internal resistors on the signal line which results in a smaller difference between signal and noise. So it can pick up noise easily.
On the other hand we know about many pilots that are using very same servos with no problem. So unfortunately in some cases and conditions they are not working well.
Few years ago we have shipped our units to BK as they offered testing of all their servos, but they stopped responding... But there are other manufacturers complaining.. But I dont wish to complain about any manufacturer. Just saying the facts.

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Spirit System developer

I currently use the following rudder servos successfully with Spirit:

Xpert R1T x2 http://hobby-square.com/xpert-r1t-quick ... ail-servo/
Xpert R2T x1 http://xpert-rc.com/product/gs-3302t-hv/
BK DS-3005HV x1 http://www.bkdesignsllc.com/product-p/bkmi02.htm
BK DS-5005HV x2 http://www.bkdesignsllc.com/product-p/bkms05.htm
MKS HBL880 x2 http://www.mksservosusa.com/product.php ... =24&page=1
MKS HBL980 x2 http://www.mksservosusa.com/product.php ... =17&page=1
Futaba BLS256HV x1 https://www.towerhobbies.com/cgi-bin/WTI0001P?I=LXBJCR

Neither one of the two BK BLS-8005HV tail servos I tried worked well. One would let the tail blow out on a 800 size heli. The other would have glitchy response on a Gaui R5 speed heli. My buddy also had tail blow out failure with this same servo using a Skookum SK-720BE FBL unit on a Velos 880. A former team BK pilot who uses Neo/VControl advised me against using this particular tail servo.

So there we have it...
Thanks for the heads up,will stay away from those.

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