Spirit System

Im resetting up my N7, and am getting a soft (2-3Hz) single or double bounce back on CW piro stops that I cannot remove.

It's uneven.

I've checked that the tail is smooth. There's as little friction there as I can manage. Checked each ball link and the linkage to the servo.

I've tried both a GS504 tail and also a faster BK8005HV. In both cases my Rudder Delay is set to 0.
I am using:

Tail gain: 1x, 80%
Cyclic Gain: 55%
Rudder Delay: 0
CFF: 4
Revomix: 0
Piro Consistency: 180-195 (tried in jumps of 5)
Headspeed: ~1950 with a multigov
Tail blades: 106mm

I've tried reducing the throw of the servo in the CW direction to little effect. As much as 4mm from the boom, which I'm aware is probably too much, but wanted to see if it made much difference. I can't say I found a definite improvement.

I've setup the heli so it hovers "ok" in rate mode. It will hold tail without any rudder input.

It holds pretty good during pitch pumps. It's the piro stops where there is inconsistency. Left stops hold very well, almost of the verge of chirping on the stop.

What can I try please?

You don't mention Rudder dynamic, which should be your friend in dealing with rudder stops... which values did you try?

Did you read this:
http://www.spirit-system.com/phpBB3/vie ... f=20&t=378

Rudder Dynamic: 7

Yes, that is what I based my tuning on today (and in the past).

So, which other Rudder dynamic values you tried?

The problem is often caused by too high Pirouette Consistency, lowering will help, but holding performance could be worsened.
You can try to decrease limit for the rudder (limit that is closer to the tail blades).
Also tail centering and servo arm can make a difference.

Can you share your whole settings, please? You can just attach 4df file and we can view it here.

Heres the setup.

I have freed up the tail as much as possible, and put 115 tails on (with 696 mains). The bounce is no longer visible. I will need to revert to 106's and test again to see if I can get the same result by upping gain and/or rudder dynamic.

Late reply to this, but I think it was all caused by mechanical. What caught me out was that by hand, while there was a tiny amount of friction it was nothing a servo couldn't overcome. You could still push/pull the slider, and it felt as though the only real friction was from some tight rubbing on the tail guides. Really, it wasn't much. I mistook that for being "good enough". After reworking the tail from servo back to the slider, making it smooth, I believe the problem went away. Yay! Thank you all for your help and suggestions.


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