Dynon Compass Calibration

I have been having a hard time getting my Dynon D180 compass to calibrate.
In the Dynon manual, to calibrate the compass module, you start with the airplane on a compass rose aligned with north. You then hit a button, wait 15 seconds while it gathers data, then turn to east, then south, then west, waiting 15 seconds each time for it to collect data. At the end of the process, while still aligned with west it completes and you're done. The compass should read 270 right! Well mine never would. It would read 255,
105, 175, and 015 for the cardinal points. It hasn't been much of an issue because I fly it VFR and I'm just a wingman so I usually just follow somebody anyway, but with no projects little squawks now can be addressed.
The airplane's twin, with a nearly identical install performs fine.
Dynon went so far as to send me a new compass module to try, no luck though!

Here's a pic of my compass installation. It is the SafeAir kit, installed in the right wing.







I have a strobe cable, an 18 ga. wire for Nav. lights and a 14 ga. wire for the landing lights running out to the wing tip all running thru the heyco snap bushings. Paralleling this wire run and about 2 inches away is another shielded cable for the compass module. I sent this pic to Dynon and Mike thought it looked good to him, but asked me to run a compass of some sort near the module to see if it would deflect. I verified to him that all the hardware was stainless, and that I didn't think the compass was necessary but I would try it.

Guess what, taking a standard spare Cessna compass and starting with it 2 feet above the module, and gradually lowering it to the module, it deflected about 20 to 25 degrees.

A beer at Oshkosh to the first person who can identify the smoking gun!

Jon, there's some metal in the hooded connector (screws, etc.), the nutplates on the rib, and there is potential for the aileron counterbalance tube to get magnetized.

Vic

That was quick, Vic! The #6 nutplates didn't do it, and the 2 little screws for the connector didn't do it.

IT WAS THE COUNTERBALANCE IN THE AILERON.

On the airplanes twin I installed the mount closer to the main spar, on this one for some reason I installed it one lightening hole further aft.

In my zeal to see if this in fact was my problem I failed to take a picture of the new installation. For anyone doing the SafeAir wing tip install, putting the mount so that the module straddles the main wing spar is far enough forward of the cursed aileron counterbalance to get a good compass calibration.

Vic, it will be a pleasure to buy another "habitual offender" the Beer of your choice!

Jon -

What were your final calibration results? On mine, It's spot on for North and South (within one degree), and the D100 reads about 93 - 94 degrees when the airplane is pointed east, and reads about 267 - 268 degrees when the airplane is pointed west. My compass is mounted in the same location as your original location. I think the compass should read a little closer, but I can probably live with it although the winds aloft will be off. If I move the compass forward a little, to the area between the most forward lightening hole and the second one aft, or up by the main spar, I am afraid I'll get interference from HID ballasts which are mounted inside the wing on the outboard nose rib.

So again, what were your final calibration results, and where is it mounted? By the spar or between the first and second lightening holes?

Thanks

serial connector to EDC-10A

I was surprised to find that the OEM serial connector to the EDC-10A is ferrous, disturbed my magnetic handheld compass. Nonetheless, I was able to get a good swing based on comparison to my vertical card compass, which is very accurate.