Hi,

I`m having difficulties comprehending what is wrong with my setup as I need conciderably higer tail gain when I go from normal at 2470 rpm headspeed to Idleup 1 at 2680 rpm.

My setup is as follows:
Devil 380
Spirit Pro
Hobbywing Platinum 80 V4
Alzrc DS501MG tail servo at 7.4V
●Operating Voltage:DC6.0V-8.4V
●Working frequency:1520us/333Hz 800us-2200us
●Speed and torque:
- 6.5Kg.cm/0.05sec/60°@8.4V
- 5.5Kg.cm/0.06sec/60°@7.4V
- 4.6Kg.cm/0.07sec/60°@6.0V

I use the Spirit governor, and has it set in a manner that gives no bogging at pitch pumps (+/- 11.5)
Have changed main pinion to 19 tooth and tail pinion to 19 tooth as well due to running quite low headspeeds.

The enclosed profile settings of Normal and Idleup 1 is what I ended todasy flying with.
Normal mode is holding tail almost perfectly with 75% gain and 1.22 common tail gain when pitch pumping.
Idleup 1 is kicking about 5 degrees at 100% gain and 1.50 common gain when pitch pumping.

What am I missing here? Shouldent it be the other way around- more rpms=less tail gain if all else is equal?
I have looked at my setup time and time again, and cannot find any reason for this behavior.

I do not have a reamer for the ball links, but the tail is running quite smooth. The lenght from servo center to link is 13mm, so dead center as per assembly manual. Fyi I have also tried at 11mm and 14mm with same results.

Edit: I have full travel in each direction on the tail.

Any help is appreciated.

Brgds
Stefan

Hi,

this is very strange, normally for higher RPM you need lower tail gain.

In any way, I have found some things in the settings that should be reconfigured.

Firstly, I recommend to decrease Rudder Delay to at least 5.
Then I recommend to decrease Pirouette Consistency to the same value that you are using for Normal mode. Value of 195 is usually too high even for 700 size helicopters.

When you are moving with the tail on the ground, do you see approximately same compensation/servo movement in both modes?

_________________
Spirit System developer

Thank you for your support.

Indeed it is strange..

I will try out your suggestions as soon as the rain stops and report back.