Garmin magnetometer wingtip mount

[rodsmith]

Reading the mounting location specs from Garmin for the magnetometer, you realize that there is no location that meets all there requirements. The wingtips seem to come closest to a good location. I struggled with designing a mount for the magnetometer that would both be rigid and provide a method of accurately aligning it to the .5 deg spec, fore and aft. I eventually came up with the idea of using a 1 1/2" x 1/8th piece of aluminum angle with a piece of .050 aluminum sheet to provide the necessary foot print. Along the way, by chance I discovered that the stainless mounting screws that come in the install kit actually have some slight magnetism ( they can be moved when placing a rare earth magnet near them). Also the dsub connector has some ferrous components. That makes me believe that Garmins warnings about proximity to ferrous materials is a little over the top. None the less, I only used brass screws, nuts and lock washers to mount the magnetometer. I used countersunk screws to mount the piece of aluminum sheet to the angle, so the magnetometer sits flush over them. Assuming the wingtip rib is parallel with the longitudinal axis of the plane, then the magnetometer should have good alignment.

DSCF2096.jpgDSCF2094.jpg

[500AGL]

I believe there is a 3* tolerance on the gmu, but don’t assume wingtip relates to level. Always take a degree reading off the level point and transfer it.

[rodsmith]

I set it at flight level. It was the azimuth that they prescribe such a tight (unrealistic?) tolerance.

[500AGL]

I think it’s 3 and 5 degrees? Pretty straightforward.

photos of brackets I bend up for the shop to use.

[Dpearson]

I’m also planning a wingtip or “first bay in” location for the magnetometer. I decided this based on comments in an EAA Homebuilders Week webinar hosted by Garmin. The presenter said that the magnetometer could deal with small amounts of ferrous material (like fasteners) nearby, but moving ferrous parts would be much more troublesome. So for me, that ruled out any locations closer to the wing root due to the aileron bellcrank and flap mechanism.

[500AGL]

Wingtips are excellent locations for the GMU.

In addition to previous posts -
-Use LEDs for tip lights/strobes. (No big strobe packs in the tip)
- home run grounds back close to the battery.

[rodsmith]

Probably not necessary, but I also ran the magnetometer wiring by itself ahead of the rear spar, instead of in the conduit with everything else.

[spinningwrench]

My wingtip install looks like Rodsmith's. The Garmin application engineer said wiring could be bundled with everything else going to the wingtip provided wingtip strobes were LED.

[svyolo]

I put mine 2 bays in from the tips. I made an inspection hatch and mounted it to the hatch.

[Utah-Jay]

I think it’s 3 and 5 degrees? Pretty straightforward.

photos of brackets I bend up for the shop to use.

I’m using Dynon, but would love to get a bracket like that if you have any extras.