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Goblin380 tail wag
Posted: Mon 27. Jun 2016 16:32:17
by demon450
Hi,
I recently set up a new Goblin 380 with Spirit. I have slow tail wag during hovering and small tail blow(like 10 degrees) during big pitch change (ex. tic toks)
I'm running bk 5005hv. I checked the forum and set rudder delay 0, piroutte consistency 170, adjust the gain on my transmitter to the max value which does not cause tail oscillating.
I also tried to use revomix at 2 but no help. I'm pretty sure the mechanic is good and all other settings are ok (this is my 3rd spirit)
Is there any other params I can adjust or any other ideas?
Thanks!
Re: Goblin380 tail wag
Posted: Mon 27. Jun 2016 17:14:43
by jgiannakas
Have you checked servo frequency for the rudder servo? What have you set it at?
Re: Goblin380 tail wag
Posted: Mon 27. Jun 2016 17:28:28
by ZeXx86
Hi,
for Goblin I recommend to set tail center position to 3-4° so that the slider is closer to the boom.
But I suspect there is unfortunately something wrong in the mechanics. It is not unusual that a new kit is not working perfectly smooth. Some helicopters must be checked very carefully when new to exclude any binding, friction, etc. Also ball linkages are often not smooth when are new. So ball miller is needed.
With your setup it should work well without any tuning. Also values you have mentioned looks good.
Especially when you see a slow tail wag during hovering, it is unfortunately always mark that mechanics is not smooth as it should be.
When rotor is spinning, situation can be very different when it is not spinning - this can be tested easily. Unmount all blades and unplug push rod from the tail servo arm.
Then you can carefully start the motor and then you can try to move with the push rod manually. There should be nearly no aditional friction in the whole travel range when everything is OK.
Re: Goblin380 tail wag
Posted: Mon 27. Jun 2016 18:00:41
by demon450
ZeXx86 wrote:Hi,
for Goblin I recommend to set tail center position to 3-4° so that the slider is closer to the boom.
But I suspect there is unfortunately something wrong in the mechanics. It is not unusual that a new kit is not working perfectly smooth. Some helicopters must be checked very carefully when new to exclude any binding, friction, etc. Also ball linkages are often not smooth when are new. So ball miller is needed.
With your setup it should work well without any tuning. Also values you have mentioned looks good.
Especially when you see a slow tail wag during hovering, it is unfortunately always mark that mechanics is not smooth as it should be.
When rotor is spinning, situation can be very different when it is not spinning - this can be tested easily. Unmount all blades and unplug push rod from the tail servo arm.
Then you can carefully start the motor and then you can try to move with the push rod manually. There should be nearly no aditional friction in the whole travel range when everything is OK.
I will try this, thanks Tomas!
Re: Goblin380 tail wag
Posted: Mon 27. Jun 2016 18:01:51
by demon450
jgiannakas wrote:Have you checked servo frequency for the rudder servo? What have you set it at?
Yes, I changed it according spec, 766us, 333hz
Re: Goblin380 tail wag
Posted: Tue 28. Jun 2016 18:39:26
by Adrian
Also make sure your headspeed is not oscillating. I did also had troubles with tail, but at the end it was caused by not well holding headspeed by governor.
Re: Goblin380 tail wag
Posted: Wed 29. Jun 2016 4:19:28
by Rcpassa
This is a relatively common problem with the 380. My problem was solved with the Lynx tail pitch slider and arm upgrade.