Oxy 3 fast tail wag after update to v2 & change motor pinion

[phwm]

My Oxy 3 had been flying well. After updating Spirit from v1.3.2 to v2, I have fast tail wag even during hovering. At the same time, I have also changed my motor pinion from 11T to 10T.

My Oxy 3 setup:
- Main blades 285mm
- Tail blades 47mm (13T)
- Motor Lynx EOX2214 v2 (4100kv)
- Talon 35 (governed at 3,500 rpm)
- Cyclic & tail servos Turnigy S306G HV
- Battery 4S
- Main gear 140T
- motor pinion 10T
- Pitch 12 degree
- Cyclic 10.5 degree

I have disabled the governor in Talon and ran a 95% flat throttle curve and lowered the rudder gain all the way from 50 to 35 and the tail wag is still there.

The tail wag is bad especially in fast forward and fast collective change.

Can help me take a quick look at my settings to see whether there is anything obviously wrong?

Cheers
Peter

[Coco66]

Well, changing your pinion you slowed down your mains, so something also changed there...

Is it a fast wag like shaking or more a hunting where the tail does not react fast enough so it overdoes?

In the second case you should be raising your tail gain, it looks like you only tried to lower it.

[mattbeau]

My Oxy is also running 4s but with castle simple gov. I'm running 12t at 3800. And Spektrum h3050/60.


The pin size should be ok for 3500 so I don't think that's an issue. What are your vibration logs showing maybe your motor is resonating at that HS


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[phwm]

The wag is 3 to 4 hz.

I did not check the vibration log. Apart from a bit of resonant vibration at about 3000 rpm, it seems to be alright.


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[Coco66]

The wag is 3 to 4 hz.

I did not check the vibration log. Apart from a bit of resonant vibration at about 3000 rpm, it seems to be alright.


Sent from my iPhone using Tapatalk

No idea what you mean with "3 to 4 hz", sorry.

[ZeXx86]

What is wrong in the settings is Rudder Delay and possibly Pirouette Consistency.
But the settings should be same for new and old version.

For your tail servo the Rudder Delay should be between 0 - 5 and Pirouette Consistency 170. Rudder Delay should help with your problem significantly. Did you used these values previously too?

Changing pinion will affect many things, but if you will reach same head speed, then it should work in the same way theoretically.
In case that you are flying with the same head speed, it is probable that because of higher motor RPM you are getting some very bad vibrations from the motor that were not present with a bigger pinion.

[phwm]

The tail wags to left, returns to center, then to right and returns to center in about half a second.

I have been using default for 450 and have not changed the system values for tail delay and piro consistency.

Now back home did a spectrum analysis. X and Z axes seemed to be fine. However, vibration in the Y-axis (aileron) was bad. If I disengaged the motor pinion from the main gear, there was totally no spike of vibration.

If elevator was fine but not the aileron, then I guess it cannot be the bearing block.

Which part should I test next?