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TruTrak yaw damper problem resolved

Tim Lewis

Well Known Member
I've been trying to resolve poor yaw damper (YD) performance in my RV-10 for 2 years. Even flew it to TT HQ, where they found a wiring error I'd made. But issues persisted, including a long period (6 sec) hard yaw oscillation.

Finally figured out that the bracket I was using for the YD control head had a little bit of flex, which must have allowed the YD head to vibrate/oscillate in flight. I screwed the yaw damper control head to the belly of the plane (with shims to keep it level). All performance problems appear to be resolved. YD now works fine. It does a great job of damping yaw induced by turbulence - far better than I can do with my feet on the rudder pedals.

TruTrak support was very good throughout the process.
 
Yaw Dampner vs. springs

Thanks for the update. I have been considering adding this but have not talked to anyone with it. I was concerned about adding weight in the back of the plane and the actual function of the unit.
Do you find that it keeps the ball in the center at different speeds? (140kts - 170 kts)

Can you turn it on with out the autopilot on?
 
Thanks for the update. I have been considering adding this but have not talked to anyone with it. I was concerned about adding weight in the back of the plane and the actual function of the unit.
Do you find that it keeps the ball in the center at different speeds? (140kts - 170 kts)

Can you turn it on with out the autopilot on?

That is dependent on which autopilot it is used with. If it is used with the Sorcerer, yes. It has an integrated control to turn it on and off, independent of the AP.

If it is used with a Digiflight II series there is not an integrated control to independently turn it on and off.

It can be wired and used as a stand alone system where you can turn it on and off at will. Let me know if you have any questions. Thanks!
 
Thanks for the update. I have been considering adding this but have not talked to anyone with it. I was concerned about adding weight in the back of the plane and the actual function of the unit.
Do you find that it keeps the ball in the center at different speeds? (140kts - 170 kts)

Can you turn it on with out the autopilot on?

Components aren't very heavy: a featherweight control head, a servo (same as the elevator servo), an aluminum bellcrank, and 3 rods with rod ends. Even with the TT Yaw Damper installed, my RV-10 (1634 lbs with full paint and panel and interior and wheel pants) was still nose heavy. I have to have 10 lbs in the baggage area to bring the CG back to the forward limit (single occupant, full fuel).

Ball centered? Yes. And in turbulence, the TT Yaw Damper does a FAR better job of countering the turbulence-induced yaw than I can do. I've noticed the difference, and so have several passengers.

On/Off: My YD is wired so that my Advanced Autopilot (a TrueTrak DF II- VSVG modified to integrate nicely with the AF-4500 EFIS) controls the YD. The YD turns on when the AP is engaged. It would be very simple to add another switch (SPDT) to have the YD on independent of the AP. Basically, you'd want to have a switch that disconnects YD pin 8 (http://trutrakap.com/documents/Yaw Damper Installation Guide.pdf) from the AP and forces it to ground. With that switch, you could turn on the YD even if the AP were off.
 
Tim, do you have pictures of your yaw servo installation? There is nothing on the OEM site and I'm trying to envision how you installed a servo in conjunction with the cables for the rudder.
 
Tim, do you have pictures of your yaw servo installation? There is nothing on the OEM site and I'm trying to envision how you installed a servo in conjunction with the cables for the rudder.

The YD in the RV-10 uses it's own additional set of bridle cables attached to the rudder cables from a capstan on the servo, so the servo isn't necessarily installed "in conjuction" (but sort of) with the existing cables.... I don't have a picture handy, but I'm sure someone does.

Cheers,
Stein
 
Tim, do you have pictures of your yaw servo installation? There is nothing on the OEM site and I'm trying to envision how you installed a servo in conjunction with the cables for the rudder.

Send me a PM with your email address and I'll send you some photos. :)
 
Post the photos here; I'm probably not going to be the last person with this question. I'm curious why this isn't on your website anyway; you've got the pitch and roll installations there.

Ok, here are some pictures for the curious.
 
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