Bumping my old thread for a PIREP. G5 and GMC507 is installed and coupled with a 430W. I have RTFM as
@SixPapaCharlie suggested. I have searched out youtube videos trying to gain insight into using the autopilot with approaches, missed, etc. I have flown with it for probably 30 plus hours. I have tweaked the settings in flight until we were nauseous. I have been in email contact with g3xpert many times in attempt to improve its performance. Unfortunately, g3xpert advised they were stumped.
The autopilot will hold course and altitude fairly well in ALT mode in level flight except when we had anything to upset straight and level - updraft/downdraft, cloud layer nearby, mountain ridges nearby, even moving in the cockpit can produce a 500 fpm climb or descent.
On climbout with NAV & IAS set for 110 kts & altitude of 8500 selected, at about 1000 feet I engaged the autopilot. It oscillated up and down significantly and my wife objected. I turned it off, climbed a bit by hand, selected 120 kts as IAS, and re-engaged autopilot. It oscillated from IAS of about 128 kts then down to about 106 kts repeating the oscillation pattern. The vertical speed during this time went from +2000 fpm to -700 fpm. This was in perfectly calm morning conditions.
Even at 100% torque setting for the pitch servo, I can very easily overpower the servo with one finger on the stick or elevator. Not sure if that is indicative of a bad servo.
There are times when the elevator servo doesn't do what I have set it to do. Not sure if I have set it incorrectly or it's just not responding properly.
In any case, we're quite disappointed with it. After reading many positive reviews I figured I would try one. At this point we're looking at removing it and reinstalling a Trio. At least the Trio held altitude reliably, I could trust it and didn't wonder what it was doing.