Compass Drifting causing autopilot issues.

[kevineldredge]

I have RV8 with D180 and AF74. After updating all components to the current version firmware system engages and seems to work pretty well once some small adjustments to the servo settings. The last problem I am facing seems to be the compass (remote). Once trimmed and stable I kick on AP and it tracks pretty well until the compass gets a little off and then AP hunts the bug. The plane flys past the bug and then corrects back past it over and over. Annoying! not a little but 10-20 degrees. I didn't build the plane so not sure how well the remote compass is installed or insulated. Any info put tracking down this last issue?

Cheers!

 

[Dynon]

So first, many people prefer to use the TRK mode (if a GPS is connected), which uses GPS ground track, instead of HDG, which uses the magnetometer, to help smooth things out.

Beyond that, find the magnetometer and make sure it's in a suitable location, away from power and ferrous metals, etc per the installation manual.

Assuming that's good, you might want to recalibrate the meg heading. It's a multi-step procedure that starts with plugging your location into an internet tool to get values that you then put into your EFIS before swinging it on a compass rose. See the EFIS-D10A's installation manual for details, and you'll need this site to grab the magnetic field numbers: https://dynonavionics.com/magnetic-inclination.php

 

[kevineldredge]

Thank you for the info. I don't GPS connected but will check out the compass itself.