GMU11 location and other wires.

[Flyboy66]

I was reading the G3X manual for the GMU installation. It has a section list of recommended distances from motors, relays, electrical devices?.

i was going to put mine in the next to last bay to keep it away from the Nav/Strobe, but J McBean said they mount theirs in the last bay. Has anyone attached it to the aft spar in the most outboard bay? I was going to route the canbus, GMU power, landing nigh wires, and nav/stobe wires through the rear spar. This appears to violate many of the minimum distance from GMU11 in the chart. John says they have no issues, but his magnetometers are mounted in a different location that where I want mine.

what are your thoughts?

steve

[bbs428]

Hey Steve,

I mounted my GMU-11 in the last bay as well. I used balsa stringers with brass hardware. The black rods are recycled carbon fiber arrow shafts.

I used M27500-18TG1T14 shielded wire from aircraft Spruce an ran it through the spar for the Nav/landing lights.
I opted to run the GMU-11 wiring harness outside the spar to give it some separation using M27500-20TG2T14 shielded wire for the can bus. The strobe circuit had me the most concerned for any induced emi. Garmin did note, as you stated, to be aware of this. It's cheap insurance as it's hard to fix after it goes together!

You can see the placement of the GMU-11 in relation to the spar in this pic from my build. I have had zero issues in 200+ hrs. of flying.
I used a lot of that mil-spec shielded wire in the build, and it paid off with no radio interference!

Hope this helps, all the best!

20200822_165032 (2020_09_21 10_29_07 UTC).jpg

[Flyboy66]

Thanks,

unfortunately, I already have fabric on the airframe. I do appreciate the info. I am waiting to see if anyone has run all of their wiring through the spar, and if so, were there any problems?

Hope this helps, all the best!

20200822_165032 (2020_09_21 10_29_07 UTC).jpg[/QUOTE]

[Kitfox Pilot]

[QUOTE=Flyboy66;113042]Thanks,

unfortunately, I already have fabric on the airframe. I do appreciate the info. I am waiting to see if anyone has run all of their wiring through the spar, and if so, were there any problems?

I ran all my wiring and tubing through the spars. No problems at all.

[Geek]

I mounted mine all the way out in the last left wing bay and ran the wiring down the spar. No issues. Pic is of the mount looking down. Mount is made so I can slide the GMU-11 out and remove it if required.

Magnetometer 1.jpg

[jiott]

Regarding wiring runs thru the spar; I used a very light weight plastic split corrugated wiring conduit to contain the wires thru the spar, to protect them from vibration abrasion especially where they must go past quite a few rivet tails inside the spar.

[Flyboy66]

I am feeling much better about the last bay now.

i really appreciate the information.

[alexM]

If you follow the manual you would need to mount it 20' from the aircraft.

I'm using MGL avionics but I went through this exercise for mounting my magnetometer and was concerned about interference from my tip strobes. The MGL tech told me I would need to route the wires within 1" of the tip strobe to make any difference in performance.

Mine is in the outer bay, with wires routed as others have done (through the rear spar). Shown here when I was using cardboard to mock up the platform I made out of a sheet of carbon fiber.
PXL_20210814_001850126.jpg

[Flyboy66]

If you follow the manual you would need to mount it 20' from the aircraft.

I'm using MGL avionics but I went through this exercise for mounting my magnetometer and was concerned about interference from my tip strobes. The MGL tech told me I would need to route the wires within 1" of the tip strobe to make any difference in performance.

Mine is in the outer bay, with wires routed as others have done (through the rear spar). Shown here when I was using cardboard to mock up the platform I made out of a sheet of carbon fiber.
PXL_20210814_001850126.jpg

I am pretty sure that need to mount it on a 10 foot, non conductive pole, oriented away from the upper surface of the right wing, to be in compliance with Garmin?..or I can do what everyone else does.