Hi,

This is my first post. I hope you can help me to find answers to my questions. I´m looking forward to hearing from you.
It´s my first set up with the Spirit FBL, as well. Here are some informations about my hardware.

Hardware:
SPIRIT RED
T-REX 470LM standard motor
380mm Align standard blades
69mm tail blades
+- 12.5 ° Pitch

ESC: RCE-BL50X no govener – 7.2V BEC-Voltage
Heck Servo: Align DS455
Cyclic Servos: TGY-306HV

Throttle curve 1 [%]: 74 69 67 69 74
Throttle curve 2 [%]: 95 84 78 84 95

2x Spektrum SAT (one with spektrum adapter)

And the settings:


Questions:

#1 How to enter the normal mode?

To adjust the tail mid-point prober, I would like to enter the normal mode via the transmitter. I asigned channel 5 of my transmitter to the gyro gain and the poti on my transmitter. On my servo monitor of the dx8 I can see that the value for this channel can be changed from -100% to +100%.
In the setup wizzard I had noticed that the channel-value for gain, can only be adjusted form 0 to 100% and it only shows the head-lock modus. How do I have to change the settings in my TX (Spektrum DX8 – SAT) or in the unit to get the normal modus for adjusting/trim the tail. I do not use bank-switching. I´m assigned a separate channel for the rescue mode.

#2 How to set up the tail?

In flight mode 1 with lower rpm, the tail is nearly perfect an do not kicks to the right side. I can adjust the gain via the transmitter to 100%. The strange thing is, that I do not see any tail oscillation with this setting even not for 100% gain.

When I´m increasing the head speed (trottle curve 2) , the tail do not hold and moves for pitch pump to the right to about 10-20 degrees. For lower gain settings it´s getting worser, but from about 60 to 100% I don not see any difference. And even with 100% I can not observe any oscillaton of the tail.

Why is the tail holding for lower rpm? I would expected, that the tail performance will be better for higher rpms. Is this behavior related to question #1? Or do I have some wrong settings of the fbl-unit.

Best regards and thanks a lot,
Hannes

Hi,

welcome in our forum!

1) you can enter the Normal mode by selecting Stabi/Function to Disabled and then when you will set negative gyro gain, it will become Normal mode. Here you can see table with explanation: http://manual.spirit-system.com/index.p ... _vs_Gyro_2
But when you will set the tail according the manual of the T-Rex it should also be OK.

2) This is because your Throttle Curve is unoptimal and motor is causing too much torque which tail can't hold.
For throttle curve 1 it is good, but for 2 difference is much bigger. So by decreasing difference of V curve, it will be definitively better.
Main rotor/motor has very big influance on the tail performance. So it is good, if it is in a good balance.
It is bad if the RPM is dropping too much and also if the RPM is getting higher than needed. Then there is very small room that the tail can work well.

_________________
Spirit System developer

#1 Normal Mode:
Thank you very much for your answer and the link that is explaining the different stabi and gyro modes. As you recommended, I deasabled the stabi mode and after that I was able to set up the tail in the normal mode. Without any trimming was turning with a a slow speed around the yaw axis ccw (top view). After tuning the tail is holding the position in the normal mode.

#2 Tail settings:
Today was testing the tail behavior for different throttle curves. I decreased the distance between the values of the throttle curve (93 88 85 88 93) even with a very flat curve (90 87 85 87 90) the tail was not holding an bouncing to the right side (view from behind / CCW from top view). Also with my first curve (74 69 67 69 74) the tail is moving but slightly better than with higher rpm curves.
The stop behavior of the yaw axis is also different. CCW (top view) I can see one small overshoot (backbouncing) and the CW rotation is perfect. I also checked the end points for the tail servo - OK. The mechanic is moving ultra smooth.
Can you please check the settings of the SPIRIT-Unit, as well?

BR Hannes

I recommend to make tail arm longer, since your limits are little bit bigger than usual.
This could also improve tail performance and stopping since the travel will be more optimal.

To improve stopping even more, you can update to version 2.4.1 which should make it better as well.

_________________
Spirit System developer

Now I made a few changes of the Hardware and the settings of the FBL-System.

Tail servo BK 3005-HV with Zeal blades 68mm
Hobbywing ESC 60A V4 (govener mode active / standard settings)


I also have change the position (from the inner to the outher hole of the align Servo horn) of the rudder arm, as you recommended.
Then I adjusted the length of the rudder rod to achieve the same limits for the left and the right position. For the rudderlimits I have excactly 100 for each side, now.
In several test flights I have adjusted the center position. At the current value the tail don not swing (small slow moving 1-2°) in hovering and the tail moving for pitch pumps is for this position got its minimum.

But, the tail is still moving to the right (10 degrees) for positive pitch pumps.

Than I add a value of 7 for the revomix and than the tail stays nearly at it´s position. In the past I was testing lower values (>4) without any influence. In other posts I red, that it isn´t recommended to use the revomix and the value should be less than four.

Can you have a closer look to my settings of the FBL-Unit, please? What I´m still doing wrong?
What are the reasons for this tail behavior?

Thanks a lot!

Today I did more testing.
First I decreased the piro value down to 150 and slowly increased it step by step.
At a value of 174 the tail had the best holding performance for pitch pumps (5 degrees).
For higher values, the tail will not get better. With revomix of 7 it is better.

Do you recommend to fly with a revomix value of 7? Can you please give a advice and have a look at the settings?

Hello,

your settings seems to be good.
But reason why it is not holding well is very likely not in the settings.
It should hold very well also with the stock servo.

So the possibilities are:
- Governor is not holding the RPM too well (or battery is not able to perform that well).
- Governor has too much gain so that the RPM is even higher than it should be during a load.
- Tail mechanics is not as smooth as it should be.

For mechanics you can do a simple test:
1. remove all blades
2. disconnect push rod from the tail servo
3. spin up the motor to flight RPM
4. move with the push rod by hand (carefully) and observe how smooth it is.
5. do you have to apply too much force?

_________________
Spirit System developer