We selected to put the magnetometer in the ceiling to drive our Dynon D10A. A while back I borrowed Wayne's huge boat compass and rested it on top of the ceiling. Then a pilot crawled in the left side with headsets on. It caused a 1 degree variation. Then we tried with both a pilot and passenger and it caused a 3 degree variation. I am thinking I can setup during calibration swing and try to zero at 2 degrees off. This way it will be off ~ one degree no matter if flying solo or with a passenger.
Dynon is adamant to have magnetometer within 1 degree to instrument in all 3 axis. Bud shoots for within 1 degree, but says those who eyeball them seem to have OK success. Steinair says being off 2.6 in roll and 1.7 in pitch should not be a problem.
After mutilating the aluminium case by bending ears, thinning down areas and of course voiding the warranty, we were able to get within 1 degree and still fit in under the ceiling panel!
Mounting is accomplished with two strips of G-10 with 4 aluminium threaded hexes held to the G-10 with flat head aluminium screws. The screws and hex are JB KWIKed to the G-10, (non removable).
The magnetometer is held to the threaded hex with removable flat head aluminium screws.
Idea is to JB KWIK the G-10 strips to the bottom of fuse and then cover the front and back edges of the G-10 strips with 3 thin plies of model aeroplane cloth.
We used a digital level to adjust pitch and roll positioning of magnetometer. For yaw, we taped a 18" ruler to the magnetometer and eyeballed it.
Y10-12-24