After some troubleshooting I've made some changes to the auto-trim and wanted to report on it.
What I found was that with the recommended autopilot settings for my G3X system, when slowing down and entering an approach the system would not settle down on pitch/speed/glideslope. I would try to adjust power for a nice controlled descent and just couldn't get it to cooperate. Tried lots of things. Finally arrived at the theory that the auto-trim was overcorrecting; as in the autopilot would want more trim, move it too fast, and then end up having to come back, then overcorrecting the other way, etc. I don't know this for sure because the system doesn't report it happening in any way.
So I flew some approaches with the auto trim off, manual trim by me. Little trim movements did a lot. The approaches were satisfactory.
Flew some with auto trim on - hard to manage. So then I decided to slow the auto trim way down. I put 100% trim speed at 65 knots, and 20% trim speed (I think that is the setting) at 100 kts. Anyway, you get the idea, I slowed it way down. The other thing I did was to make the % of trim speed at those speeds a lot slower. My thought was to give the auto system more time to incorporate the trim changes in the control loop feedback computation.
Now it flies on approaches just like it should. I'm going to tweak it some but I'm pretty happy as is currently after today's test on a gusty day. Troubleshooting this has been a little difficult because you can only change some of these settings with a G3X config mode reboot and I've not wanted to do that in the air. So it has been somewhat iterative between ground stops at home.
Happy to answer questions. I'm going to keep playing with it.
What I found was that with the recommended autopilot settings for my G3X system, when slowing down and entering an approach the system would not settle down on pitch/speed/glideslope. I would try to adjust power for a nice controlled descent and just couldn't get it to cooperate. Tried lots of things. Finally arrived at the theory that the auto-trim was overcorrecting; as in the autopilot would want more trim, move it too fast, and then end up having to come back, then overcorrecting the other way, etc. I don't know this for sure because the system doesn't report it happening in any way.
So I flew some approaches with the auto trim off, manual trim by me. Little trim movements did a lot. The approaches were satisfactory.
Flew some with auto trim on - hard to manage. So then I decided to slow the auto trim way down. I put 100% trim speed at 65 knots, and 20% trim speed (I think that is the setting) at 100 kts. Anyway, you get the idea, I slowed it way down. The other thing I did was to make the % of trim speed at those speeds a lot slower. My thought was to give the auto system more time to incorporate the trim changes in the control loop feedback computation.
Now it flies on approaches just like it should. I'm going to tweak it some but I'm pretty happy as is currently after today's test on a gusty day. Troubleshooting this has been a little difficult because you can only change some of these settings with a G3X config mode reboot and I've not wanted to do that in the air. So it has been somewhat iterative between ground stops at home.
Happy to answer questions. I'm going to keep playing with it.