All,
I have a dual G3X Touch system with pitch and roll autopilot servos and a GMC305 autopilot control panel. I've performed the setup procedures when I first powered up the panel and everything worked fine. Subsequent to that, (almost) every time the autopilot is powered (but not connected) I cannot use the manual trim. If I pull the CB to the autopilot, the trim works fine. Right now, I pull the AP breaker before I fly (so I can trim) then set the breaker and engage the AP and it trims fine on its own.
My setup includes a relay board which toggles the polarity of the manual trim signal, which passes through the pitch servo, to a relay which then provides power to the trim actuator. The added relay was needed due to the higher current (greater than 1amp) which the Garmin servo can provide for trimming.
We thought it was a servo problem and replaced that under warranty. It worked fine when the tech left, but without touching anything else, it stopped working before the end of the day. When I got the tech on the phone a few weeks later to help debug, it worked fine! Next weekend it didn't work and hasn't worked since.
The fact that the trim works manually (every time) when the AP is not powered indicates that the wiring is good. When the AP is powered and engaged the servo controls the trim actuator fine. The AP disconnects when the manual trim switch is pressed. So that seems to be wired correctly as well. I'm stumped/frustrated about why I can't manually trim with the AP powered but not engaged?
Anyone had a similar issue or have any idea what might be causing this?
Thanks,
Don
I have a dual G3X Touch system with pitch and roll autopilot servos and a GMC305 autopilot control panel. I've performed the setup procedures when I first powered up the panel and everything worked fine. Subsequent to that, (almost) every time the autopilot is powered (but not connected) I cannot use the manual trim. If I pull the CB to the autopilot, the trim works fine. Right now, I pull the AP breaker before I fly (so I can trim) then set the breaker and engage the AP and it trims fine on its own.
My setup includes a relay board which toggles the polarity of the manual trim signal, which passes through the pitch servo, to a relay which then provides power to the trim actuator. The added relay was needed due to the higher current (greater than 1amp) which the Garmin servo can provide for trimming.
We thought it was a servo problem and replaced that under warranty. It worked fine when the tech left, but without touching anything else, it stopped working before the end of the day. When I got the tech on the phone a few weeks later to help debug, it worked fine! Next weekend it didn't work and hasn't worked since.
The fact that the trim works manually (every time) when the AP is not powered indicates that the wiring is good. When the AP is powered and engaged the servo controls the trim actuator fine. The AP disconnects when the manual trim switch is pressed. So that seems to be wired correctly as well. I'm stumped/frustrated about why I can't manually trim with the AP powered but not engaged?
Anyone had a similar issue or have any idea what might be causing this?
Thanks,
Don