Adding a 3rd axis servo (Yaw Damper)

porterjames

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Sep 26, 2016
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My question is to Dynon.
I added a third servo (Yaw Damper).
Since then, the flight data that I upload to Savvy seems to have changed somewhat. None of the data is reported about the engagement of the Yaw Damper. Further, the data seems to have changed. As I recall, when reviewing the autopilot engagement, the graph would show when it was and was not engaged. Now the data shows the autopilot is engaged during the entire flight without interruption, even during periods when it is disengaged. Maybe I just don't correctly remember the before and after information, but it seems that there is a change.
I wonder if the addition of the Yaw Damper has encroached on another data field.
 

dougnlina

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Mar 28, 2014
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So I installed a yaw damper a year or so ago. I just looked at my Savvy Data. Before the YD install, the AP engaged graph would show the disengagement of the AP in flight (and before landing). Now post YD, any flight where I engage the AP, it shows the AP as engaged for the entirety of the remaining portion of the graph, like it has never been disengaged. I have not really noticed any other issues with other data fields, but truth is I don't really study it as much as I did during the early hours of flying the airplane. The YD can be engaged independently of the other two axis, I wonder if once it has been "activated" once, if the system always thinks it is on, kind of a stand-by mode.
Alternately, I cannot tell by my graphs if the Flight Director is toggled on or off. On some flights I turn it off after disengaging the AP, but on most I leave the FD on. Perhaps the AP graph in Savvy shows as engaged anytime the FD is active?
Who knows, but at least I can validate that there is some difference in your data pre and post YD installation.
DP
 

porterjames

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Sep 26, 2016
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Thanks, that seems to verify my early experience.
My only other experiences is that if I only use YD the system issues multiple audio announcements that the YD is engaged. That only occurs when the YD is the only axis engaged, not when the other servos are also engaged.
Also, in smooth air to light chop the entire system functions very smoothly, but in more turbulent air, the roll servo and YD quickly become wildly out of sync and begin oscillations of increasingly greater corrections. It must be disengaged or the YD must be disconnected. I'm sure the new firmware update will solve the roll and pitch issues (along with further pitch and roll adjustments on my part). Hopefully the YD will also have some work. I have reduced the sensitivity and gain, which did help somewhat.
 

dougnlina

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Mar 28, 2014
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I cannot say that I have managed to dial in the YD. It works fine with moderate bumps but even in still air, the coordination between the YD and the roll servo is off. Any increases in sensitivity just make the system twitchy. Overall the performance is adequate but nothing I would brag about. Unfortunately, Dynon has never updated their autopilot tuning guide to include the YD or to adjust the Roll settings for better YD coordination. There are a few threads on the forum (one I think I either started or participated in) on tuning the YD, but it is a little frustrating knowing that a technician who knew what they were doing would probably be able to dial in the system much better than where I currently have it.
 

kellym

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Sep 29, 2013
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Try these settings
100%
2
2.5
0.015
0.9
Thank you for those suggestions. Quite a bit different from what I had on my RV-10. I am assuming those are settings you use for your RV-10.
I will try them out.
 

porterjames

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Sep 26, 2016
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Thank you for the suggested YD settings.
I used them as well as changing my roll settings per another thread. Although my test flight this morning was is smooth air (so I really was not able to compare to my previous settings) I was impressed.
 

porterjames

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Sep 26, 2016
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Any new suggestions on YD settings with the firmware 16 update?
I can't find any Dynon default settings for the YD with the 16 update, so I can't compare the differences.
I flew yesterday with the 16 update and the YD seemed to function fine, although it functioned fine with these settings before the update.
Any new suggested changes to these settings would be appreciated.
 

DBRV10

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Jun 15, 2008
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Location
Brisbane, Qld. Australia
Bet patient :) I have not even installed it yet.

I have not tried the new V16, and it may be slightly different to my Beta test version, but I dare say the YD is not any different. But I do not know for sure.
 

porterjames

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Sep 26, 2016
Messages
56
I flew in gusty winds and ended with a coupled approach with glide slope active. Previously, tracking was always good but pitch was always rough with several pitch slip messages (in rough air). The new firmware resulted in a very impressive glide slope capture and track. Rock solid needle with no pitch slip messages. Very impressive.
The only thing that confounds me now is the new trim (pitch) adjustments. I read the section in the new manual as well as on he Skyview screen when adjusting and it still is not clear to me what the new adjustment does. I am supposing it is sensitivity that is being adjusted. The default is 1 but it can be adjusted to 15.
 

KenLeonard

New Member
Joined
Oct 8, 2005
Messages
11
So I installed a yaw damper a year or so ago. I just looked at my Savvy Data. Before the YD install, the AP engaged graph would show the disengagement of the AP in flight (and before landing). Now post YD, any flight where I engage the AP, it shows the AP as engaged for the entirety of the remaining portion of the graph, like it has never been disengaged. I have not really noticed any other issues with other data fields, but truth is I don't really study it as much as I did during the early hours of flying the airplane. The YD can be engaged independently of the other two axis, I wonder if once it has been "activated" once, if the system always thinks it is on, kind of a stand-by mode.
Alternately, I cannot tell by my graphs if the Flight Director is toggled on or off. On some flights I turn it off after disengaging the AP, but on most I leave the FD on. Perhaps the AP graph in Savvy shows as engaged anytime the FD is active?
Who knows, but at least I can validate that there is some difference in your data pre and post YD installation.
DP
Just received the third servo (capstan) to put on my rudder. The wiring diagram speaks specifically to elevator and roll servos but nothing about yaw damper although it appears to require a different wiring setup. Where do I find the wiring diagram for yaw servo?
 

porterjames

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Sep 26, 2016
Messages
56
Just received the third servo (capstan) to put on my rudder. The wiring diagram speaks specifically to elevator and roll servos but nothing about yaw damper although it appears to require a different wiring setup. Where do I find the wiring diagram for yaw servo?
I used a capstan for my rudder. The wiring is identical to the other servos, Black-ground, Red-power, yellow-disconnect. The others go to the Skyview network connector.
In the set up you will identify the servo with rudder inputs, left and right.
 
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