Hi,

I can't solve the following issue and it would be great to have some help/ideas how to solve it.

After initializing the tail servo moves to one side to the programmed limit. It is always the same side.
The servo moves very slowly in very small steps. It isn't a continuous movement more like a step motor.
Vibration cannot be an issue because it happens on a workbench and the motor is not running.
Also I noticed that the helicopter would like to turn around, like a piro during spool up.

During flight everything seems to be ok but I'm not sure if I have a gremlin in the system...

Thanks
Guido

Using Spirit diagnostic page, check the value of the rudder channel. Should be 0 when you are not touching the stick. If not zero, the commanded movement will probably cause your symptom. Can be caused by a trim. If you have no trim, maybe your sticks need to be calibrated.

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Oxy 2 ♦ X-Vert ♦ Warp 360 ♦ Blade 450X ♦ Blade 450X Nightflyer ♦ Goblin 500 (RIP) ♦ 2 X mCPX v2 ♦ night fly mQX ♦ LadyMQX ♦ nano QX ♦ nano QX FPV ♦ Inductrix ♦ DX8 G1

Hi,

Thanks.
I checked it today. No inputs to rudder without touching the sticks.
But another pilot found a mechanical issue with tail pitch slider on my goblin 500 Sport.
It was not really a binding but a screw on one link was too firm.
We corrected it and the problem seems to be solved.

I had only two flights to verify, but it seems to be much better.
The tail is only moving a few degrees after take off. I think on a windy day that is normal.

It seems the tail is more sensitive during motor spool up with higher tail gains.
Is that correct?

Thanks
Guido

Hi,

the tail should not move at all during hovering or in any other case if it is in head lock mode. It is necessary that there is 0% in the diagnostic tab in the rudder input. Do you see "HL" in the Diagnostic tab?
What value did you set for stick deadband (Advanced/Expert settings)?

Can you measure vibrations on the Z axis with a spectrum analyser?

Is the helicopter absolutely without a movement when it is initializing?

_________________
Spirit System developer

Hi,

I will check this in about two weeks and let you know.
Unfortunately I have no chance to do this earlier.

Thanks
Guido

Hi,

just checked:
Diagnostic Tab: Rudder = 0 (at any time as long as I don't touch the stick)
Advanced: Stick Deadband: 6
Gyro: HL (at about 65% * 1.0)
Z-Axis vibration, please see attached pictures (different RPM)

This time the heli was without any movement during initialisation. On the field it might be that I mounted the canopy during that phase.

Since we removed the "binding" the servo stopped moving on the workbench.

I cannot test it on the field because of the bad weather.

Do you think the vibration level is OK?

Thanks
Guido

Great!

The plot that you have posted looks good - not completely good, but there is nothing major.
It looks like there is some small bearing issue in the rudder. Then you can see spikes on the rotor head, more on the rudder mechanics and very slight on the motor.

If it is really a bearing, then it might be worse during flight (when it is heated).

_________________
Spirit System developer

Hi,

thanks for your help.
I will let you know how it works in the field as soon as the weather is good enough for a few flights.

Thanks
Guido

Hi,

yesterday I had some time to test my goblin with the Spirit pro in the field.
On workbench I don't have any rudder servo movement after initialization. That issue is solved

But during spool up the heil would like to rotate CCW a little bit. That shouldn't be an issue but because of the long gras and the new landing gear the goblin 500 sport has a tendency to tip to the right.

After launch the heli turns about 10° CCW and stops. There are no issues during flight and landing.
The tail holds perfect even in 2min hover with some crosswind.

Maybe this is normal...

I'm using a Hobbywing 100A V3 ESC with about 11sec start up.

Thanks
Guido

When you spooling up the helicopter your tail slider should be approx. in the center or rather in the 1/3 closer to the boom.
Then it will not move at all during spoolup.

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Spirit System developer