Autopilot Wandering in Heading Mode

[olympiashorts]

Hello,
I have a new plane with the G3X Touch, GMC 305 Autopilot controller, GSU 25 ADHRS and GMU 22 magnetometer. I've never flown with an autopilot before I got this plane and I've got about 20 hours in it now. I generally used the HDG mode when I first started fiddling with it and everything seemed fine. I was out the other day and noticed that in HDG mode the plane was wandering all over the place (as much as 25º in either direction until it finally settled down). I was used to seeing it capture the heading without much difficulty. I switched to NAV mode and it grabbed the course and remained dead nuts on. I downloaded the flight data and confirmed the excursions. Any thoughts?

 

[Neal]

Welcome to Flightinfo.com @olympiashorts! Looking forward to hearing about your experiences with your new NX cub. As to the autopilot, my suggestion is to adjust the gains. If you go into the G3X menu (menu menu, setup I think is the area) then find the autopilot option you'll see the two options for autopilot and the gains. My guess is you need to increase the values so the autopilot will be more aggressive. I'm not at my plane so I can't see what my values are but maybe you can compare with someone else. I know @craig.roser dialed his in and maybe he or @Tsquared can help. I know on mine it was way too aggressive and I compared settings with @Tsquared to get mine figured out.

 

[olympiashorts]

Welcome to Flightinfo.com @olympiashorts! Looking forward to hearing about your experiences with your new NX cub. As to the autopilot, my suggestion is to adjust the gains. If you go into the G3X menu (menu menu, setup I think is the area) then find the autopilot option you'll see the two options for autopilot and the gains. My guess is you need to increase the values so the autopilot will be more aggressive. I'm not at my plane so I can't see what my values are but maybe you can compare with someone else. I know @craig.roser dialed his in and maybe he or @Tsquared can help. I know on mine it was way too aggressive and I compared settings with @Tsquared to get mine figured out.

Thanks Neal. I'll go down and get those current settings soon and will fly it again and see if I can replicate it.

 

[Neal]

I think you may see a gain of around 1.2. Try changing it to 2.0 for starters.