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unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 15:48:36
by urgno
hello
trying to find a good tail gain on trex 600 with spirit 2
but even at 100% gyro gain
i get a 90° tail jump ( tail to right ) on any pitch pump
tail servo is savox sb-2272mg
Re: unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 16:24:56
by ZeXx86
Hello,
you can try to increase Gyro Common Gain. This will multiply normal gain.
Re: unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 16:37:01
by yufasa
What rudder servo do you have? If it is a fast servo what value do you have for Rudder Delay? Default of 5 is not ideal for fast servos.
Re: unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 17:25:09
by urgno
rudder servo is savox sb-2272mg
and common gain is already at 1.20
rudder delay is at 0 or 1
Re: unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 18:19:53
by ZeXx86
It is also very likely your mechanics is not working properly. If you can see such bad behavior then it is almost certain.
Alternatively your servo arm length is wrong. What are values of the end-point limits?
Re: unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 19:05:35
by urgno
mechanic was hard but that has been fixed
rudder limits are 145 - 155
btw, raising the common gain to 1.40
and configuring gain on tx at around 90-95
finally led me to some oscillation
but only in idle2 at 2300 rpm
and tail is still not so precise
btw thanks to all for the help

Re: unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 19:10:21
by yufasa
Hmmm, so at 2300 you still have tail blowout or do you have another symptom?
Re: unable to have a stable tail on spirit 2
Posted: Sun 16. Aug 2020 19:25:12
by urgno
at 2300 little tail blowout at less than 90%
at 95% tail oscillation
Re: unable to have a stable tail on spirit 2
Posted: Mon 17. Aug 2020 9:12:11
by thestructured
If running the governor, the gain could be too high or too low for response gain.
Your tail thrust bearings could be worn out.
The tail servo could be going bad.
How much collective pitch are you running?
What is piro consistency set to? I would start off around 155 and only turn up main tail gain as much as possible first. If it's already low or default then check the things above.
Re: unable to have a stable tail on spirit 2
Posted: Mon 17. Aug 2020 9:19:23
by ZeXx86
For this model piro consisteny should be around 170. Not more than 180.
Yes, governor could play a big role too.