Hi all,
I hope someone can help. I have a belt driven Gaui x3 and a problem which I have been unable to fix.
On clockwise piro's I get a slight overshoot and bounce back (around 10degrees) every time, anticlockwise the tail stops solidly.
I have tried every thing I can think of, mechanically and settings wise to fix it but it's always there and it's always (as far as I can tell) the same amount of bounce. Setup is smooth with good bearings and no binding, below is what I have tried over a period of about three months.
- Different headspeeds, different sized tail blades, different speed servos, different belt tensions, different length servo horns, varying amounts of servo horn offsets as well as square(as recommended) and no drift in rate mode setup, varying amounts of servo travel (end points). Software wise I have changed, servo speeds, pirouette consistency, delays, flying style, rate, dynamic, all with no Revomix. Vibration is extremely low (I'm very fussy with that) and I've also tried all manner of gain settings without change.
I do hope someone can help?

Gman

Hi Gman,

can you send your settings, please?
So we know where to start.

Did you tried lowering limit to the side, where you can see overshoot? This solution should work always.

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Spirit System developer

G'day ZeXx86

Please find attached my current settings.
I have tried changing the endpoints, but just to be clear so I'm not making it worse, if it is overshooting on a right hand upright piro', which side would you recommend to reduce the travel on when looking from the tail forward?

Gman

Thank you for the settings.

First I recommend to decrease Pirouette Consistency value to approx. 170. For 450 size heli it is too high. Value between 160 - 175 should be good.
If it is too high, it will cause overshooting and too agressive behavior of the rudder generally.

Then, depending on your servo, I recommend to set Rudder servo frequency to 333Hz - each rudder servo should handle it.
What servo do you use?
Then I can also tell you how to set Rudder Delay.

You can find correct values also in our Servo list here:
http://manual.spirit-system.com/index.p ... Servo_list

If it is Clockwise rotation, then decreasing Right limit should help. This is where rudder mechanics is usually too strong, because there is too much room for corrections (much more than for the opposite side). You can decrease Right limit to 80.

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Spirit System developer

Thank you,

I have adjusted to the settings you recommended and it made a slight difference so I have spent the day playing around and the tail is much better but there is still a slight bounce back. I have a BK5001 servo on the tail and KST215 cyclics and I have attached the latest settings for you to have a look at.

Gman

deleted

Gman: Thank you for the settings.

Please try to decrease the rudder end-point until the problem disappear. But on the left side it is important to have enough range so that tail can hold even in high load.
Also I recommend to set Rudder Delay to 0 - 3.

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Spirit System developer

Hi,

I've set the rudder delay to three and I have reduced the right hand limit gradually all the way down to 50. As it gets lower the tail stopping gets softer but still overshoots.
The tail is not bouncing or wagging, it simply overshoots then corrects back to where it should be, on right hand piro's only.
I do use a governor for head speed and I have tried turning that off as well during testing but it made no difference.
Like I said in my first post it is driving me crazy

Gman

If it is returning back, it is sign of too low Gyro Gain.
It is very important to increase it as high as possible until starting tuning other aspects of the rudder. Then do not decrease the Gyro Gain anymore, if the holding performance is good (it is not moving during pitch pumping, etc).

So that there will be hard stop always, even with oscillations. So the goal is that the tail will hold perfectly first.
Then stopping should be tuned.

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Spirit System developer

That did the trick!
I had tried gyro gains in the TX from low to high and it didn't make a difference.
With your tip though I increased the rudder common gain (I thought I was not suppose to mess with this setting according to the software help bubble) I then re-adjusted the TX gain and all is good now.
Since both stops are now equal, I was able to fine tune all of my other settings and my X3 is flying nicely.
Thank you once again for your excellent service!

Gman