Dynon HDX and Trutrak AP - how to increase the banking angle?

[9krpm]

I have 2x HDX EFIS connected to my Trutrak AP.

Everything works beautifully. However in the skyview AP mode the Trutrak only turns at 15 degrees rather than a true rate 1 turn. It does rate 1 turn in other modes Nav mode with the Avidyne IFD540 and Garmin GNS430

Can any one suggest some setting changes on either unit please?

 

[Rhino]

Out of curiosity, what software version are you running? Although your symptoms aren't the same, some definite issues have been reported with autopilot operation in V16.2.4. Are these TruTrak servos?

 

[9krpm]

I think my say Version 15 but I'm not entirely sure. Upgraded the head unit around 2 years ago.

Yes truetrak servos.

 

[Rhino]

Then you don't have 16.2.4, so that isn't the issue. The wiring to the servos is not the same for the HDX as it was for the TruTrak, so that's a possible issue, but I doubt it. If you aren't using the HDX to control the servos at all, but still relying on the TruTrak autopilot for that, then wiring isn't the issue. My impression is it's a configuration issue, but I'm far from being an expert on HDX interfacing with TruTrak autopilots. If someone more knowledgeable in that regard doesn't chime in here, I suggest contacting Dynon Support.

Dynon Avionics | Contact Dynon

Contact Dynon Avionics with questions, customer support or technical help with your SkyView system or EFIS systems.

www.dynonavionics.com

 

[jakej]

I'm having the same issue - it's a problem with the NMEA datastream from the SV, IMO. Most of the time i can see it trying to work & have had it work properly on 1 short flight.

 

[9krpm]

Then you don't have 16.2.4, so that isn't the issue. The wiring to the servos is not the same for the HDX as it was for the TruTrak, so that's a possible issue, but I doubt it. If you aren't using the HDX to control the servos at all, but still relying on the TruTrak autopilot for that, then wiring isn't the issue. My impression is it's a configuration issue, but I'm far from being an expert on HDX interfacing with TruTrak autopilots. If someone more knowledgeable in that regard doesn't chime in here, I suggest contacting Dynon Support.

Dynon Avionics | Contact Dynon

Contact Dynon Avionics with questions, customer support or technical help with your SkyView system or EFIS systems.

www.dynonavionics.com

Thanks for sharing your thought. Yes I agree with your logic.

There are a lot of Dynon users with this setup when the Dynon AP was not certified. I chose to stay with this setup so I have an extra redundancy on my system. I was hoping that someone had similar experience and found a quick configuration fix (on either or both units) when I posted on this forum.

The Trutrak does rate 1 turn when in track mode and GPSS mode (from the Avidyne or Garmin GNS430 Nav sources). It works perfectly. The lateral setting is "Mod" on the Trutrak setup. So there is not any problem with the wiring.

The issue I have is that in the Skyview mode where the data streams from the Dynon for the lateral heading/GPS track, vertical speed and altitude controls. The lateral roll seems to be limited to 15 degrees rather than a true rate 1 turn in both heading or GPS track mode. I am IFR rated so when radar vectored in the CTA, I had to disengage the autopilot, hand flied this part to maintain the rate 1 turn then re-engaged the autopilot or sometimes I could not be bother and just put left it in track mode with the Nav unit and adjusted it according to the windrift for the correct radar vector.

I wonder if Dynon or someone had a quick fix for this to reduce the workload?

Yes I agree with Jake. The Dynon and TruTrak interface could do with some tweaking. The Trutrak is a great and simple to use unit otherwise especially for VFR.

 

[Dynon]

There's a chance this is wrong (since we know know the innards of the TT autopilot). But, when you're in GPSS mode, the navigator actually asks for bank angles to the autopilot. In effect, it's part of the command loop, and so that's why you're seeing that behavior. In contrast, the NMEA data basically says "you're this far off course" to the AP, and so the TT needs to do more processing on its end. There's no reason that it has to be limited to 15 degrees, so you might see if there are any settings on the TT that allow you to change that. But there's nothing we can do on the data stream side - we follow the NMEA standard that the device is looking for.