Yaw Damper for RV10

[GaryK]

Lawrence,
That's for the settings explaination. Most make sense but the AY gain is somewhat of a mystery.
My settings are:
Torque. 90
Sensitivity 4
Rudder Gain .2
Rudder Rate 0.020
AY Gain 0.005

It seemed when the sensitivity was higher the rudder was too active.

BTW.
My pitch and roll servos are perfect after using the AP guide.

Gary

 

[led]

Gary,

Sounds good. What behavior are you trying to tweak?


--
Lawrence Doan
Aeronautical/Autopilot Engineer

 

[GaryK]

The sensitivity just seems to be set too low compared to the roll and pitch axis.

Gary

 

[woxofswa]

DO NOT USE THE DEFAULT SETTINGS!

I had searched the support software to no avail so I tried my Y/D out in my RV10 this morning with just the default settings.
Holy Moly, the tail started oscillating back and forth in pure flutter mode stronger with each oscillation. I was grateful for the shutoff switch.
After landing at my cheap gas spot, I searched for more info and left a message for tech support. Fortunately, I stumbled upon this thread and I put in Gary's settings. The biggest change was the AY gain where Gary has .005 and the default was 1.0 Huge difference.
Once airborne again I mustered the courage to turn it on again and to my delight, it worked quite nice. Pretty cool actually. Huge thanks to GaryK! I would recommend that everyone start with Gary's settings. Later when Dynon called me, I recommended the same.

 

[led]

The default AY gain is supposed to be zero, we'll look into what's going on. Thanks for bringing it to our attention.

--
Lawrence Doan
Aeronautical/Autopilot Engineer

 

[led]

YD defaults and adjustment

RV-10 Defaults

    Yaw Sens: 5
    Rudder Gain: 0.25
    AY Gain: 0
    Rudder Rate: 0.005

Adjustment process

    With AY Gain zero, engage YD and observe behaviour.  If any oscillation or snaking occurs, turn down Sensitivity until it goes away.

    Once Sensitivity is set, observe 'tail wag' behaviour.  One way to do this is to engage the AP in HDG or TRK mode and kick the rudder to get the ball off center, then engage the YD after releasing the rudder.   The nose should quickly settle down compared to the same kick with the YD off.  Gradually increase RUDDER GAIN to increase damping.

        If increasing RUDDER GAIN does not produce an improvement, increase Sensitivity and try again.

    Initiate turns in HDG or TRK mode.  With the YD on there will be a slight hesitation as the bank starts.  If this is excessive, increase AY gain slightly, or reduce RUD GAIN.

    RUD RATE should be adjusted so that the the ball is trimmed to the center in approximately 30 seconds to one minute in level flight.

 

[led]

It looks like there's a glitch in setting updates that can cause AY Gain to be incorrectly set to 1, so please use the defaults in the above post.

The default AY gain is supposed to be zero, we'll look into what's going on.  Thanks for bringing it to our attention.

--
Lawrence Doan
Aeronautical/Autopilot Engineer

 

[GaryK]

Lawrence,
I'll try the above and fine tune.

Woxofswa,
I had the exact same experience. Was also glad I installed the YD on/off button!! The YD definitely helps in turbulence. I know people think it may be overkill but it's just another tool in my book. The YD does an amazing job of keeping the ball centered in the climb. Really nice to be able to switch it on while hand flying the pitch and roll.

The install directions from VANS are good, I did vary in one area. Trying the get the spring clamps to hold the rudder cables tight enough just wasn't working for me. Had my wife apply moderate pressure to the rudder pedals while seated in the copilot seat(rudder was clamped straight) while I installed the bridle clamps. Worked like a charm with no slop.

Gary

 

[tucsonphil]

Very interested in putting a Yaw Damper in my 10. Can not find the Kit on Van's site. Anyone have the link?

 

[GaryK]

Not sure if you still need this
Vans Part number:
14 SV AFS SERVO INSTAL KIT

The plans will be:
Manual-14 Section 58

Gary

 

[GaryK]

Phil,
The Vans instructions are very good. Two things I did differently during the install, both very minor.

Instead of taping the rudder to the vertical I used a cushion clamp on the top of the rudder and vertical. You need to have it centered and solid so it doesn't move

The instructions have you use spring clamps just forward of the F01407-L and R to hold the rudder cables taunt when the Bridle harness is installed. I found there was too much play doing it that way. Had my wife sit in the co-pilot seat and apply moderate pressure to the rudders to keep the cable taunt. The rudder was calmped to the vertical so didn't need to worry about it being centered. I found it much easier to install the bridle clamps that way.

The Yaw Damper works exceptionally well. I would recommend connecting a momentary switch to the yellow wire. You can then use the YD independent of the AP.


Gary

 

[woxofswa]

I had a chance to try out the YD over a 17 hour OSH round trip and overall it was a nice improvement. During cruise I turned it off for a bit to allow a slightly skeptical wife an opportunity to compare and when I turned it back on she (we both) agreed that it improved the ride so I'm happy with it.
One thing I am sorting out now is that my nav tracking seemed to wander a bit more than I have ever noticed before and I am wondering if the YD plays a part in that. It was very gently chasing back and forth +/- 5 degrees, especially with a crosswind. Maybe the YD requires a touch of roll tweak to get perfect.

 

[JoshT]

Does anybody have pictures of the installed yaw damper and its associated bracket from Van's? I'm doing some planning, and am especially interested in seeing what space it takes up that might interfere with other systems.