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Magnetometer Location

asw20c

Well Known Member
I'm up to my ears in the empennage/tailcone build, but I thought it would be prudent to consider installing any hardware/wiring harnesses/brackets at this stage for future avionics capabilities rather than waiting until when it will be harder to crawl back there. My C180 has Garmin avionics so I plan to stick with what I know (Garmin) when I have my panel built for the -14. Therefore I thought a call to Stein Air was in order. After chatting with them I learned that some folks install their magnetometer in the fuselage, and others in a wing. For the life of me I can't see an argument for one over the other. Can someone share with me their logic for choosing fuselage vs wing? I understand that I don't actually have to buy the magnetometer now if I choose to put it in the fuselage, rather I can simply install the mounting ring and wires. Still, if it makes more sense to mount in a wing then I'd rather wait until I'm at that stage.
 
The RV-14 wing kit comes with a cool ADHARS mount that goes in the left wing. It is designed for a SkyView module (or two modules) to slide in an clip in place. I believe the also fit the Garmin ADHARS modules but do not know for fact.

Carl
 
Certainly no expert here, but from my understanding there is more ferrous metal in the fuselage than in the wing in most aircraft. I think it's easier to find a clear area in the wing. But it's probable easier to mount and run the connections in the fuselage.
 
I built a bracket to fit inside the longitudinal brace between the baggage bulkhead and the roll bar. Pretty far from all ferrous components.
 
Clay,

According to Van's avionics letter from last summer (https://www.vansaircraft.com/pdf/letters/RV-14_Avionics_P9_Final.pdf) they are working on a GMU 22 magnetometer mounting kit that will allow you to install the Garmin magnetometer in the ADAHRS mounting platform in the left wing (the platform is already part of the standard wing kit). It's my understanding that Vans performed the Garmin magnetometer survey on the RV-14A and found this location to be a good one, and Mitch Lock also told me that he's had good magnetometer performance in the G3X-equipped RV-14A demo plane.

There are several advantages to using the wing-mounted location. It's already been designed for you (with a mount that is level and aligned with the aircraft longitudinal axis) so there's nothing to invent, fabricate from scratch, or mess around with alignment concerns. It has already been surveyed for you so it's a known quantity with respect to performance. It may also be lighter weight than an aft-fuselage installation depending on how it is done.
 
I put my magnetometer in the wing for a few reasons.

It plugs straight in to the supplied wiring for the wing.
Supposedly less interference.
The less I have to do in the tail the better - I just don't fit.
The ADAHARS mount is there ready to use.
That's the way the Vans team did it.

Having said that I wish I had made the magnetometer mount that slips in the ADAHARS mount before I closed the wing. It would have been much easier. When Vans make that part available that won't be a problem for others.
 
I bought the magnetometer bracket from Garmin and riveted it to the ADAHARS mount in the left wing before closing up the wing. 3 or 4 screws to install the magnetometer through the inspection hole (or wing root), plug into the wing harness provided.
 
As Mark said, I have the GMU22 mounted in the left wing, as per plans, and have had flawless performance from it.
 
Easy to re-use the ADHRS location

It's pretty easy to adapt the ADHRS mount in the left wing for the GMU-22. It's also fits nicely with the Van's wiring. The Garmin part you need is:

Garmin GMU-44 Universal Mount Kit P/N: 011-01779-01

You can find them on ebay brand new for pretty cheap. However I would recommend getting your hands on the GMU-22, or at least the mounting ring that comes with it prior to closing up the wing. The mounting ring (included with the GMU-22) needs to be riveted to the Garmin bracket, which is riveted to the ADHRS bracket. I can take some pictures of my install and send them to you if it would be helpful.
 
Wing mount

As Mark said, I have the GMU22 mounted in the left wing, as per plans, and have had flawless performance from it.

Mitch - is there a section in the plans that describes using the AHARS mount for the GMU22? My wings are fully skinned but I believe there is plenty of access room to do whatever I need to do. Mainly curious if adding the GMU mount is an easy task and if I can source the materials from Vans.

Jared - just saw your post as I was finishing mine. I'll PM you my email if you wouldn't mind sending pictures of the mount.

Thanks, James
 
Mitch - is there a section in the plans that describes using the AHARS mount for the GMU22? My wings are fully skinned but I believe there is plenty of access room to do whatever I need to do. Mainly curious if adding the GMU mount is an easy task and if I can source the materials from Vans.

Jared - just saw your post as I was finishing mine. I'll PM you my email if you wouldn't mind sending pictures of the mount.

Thanks, James

I think an optional kit and drawing is about to be released that will cover this.
 
Picture of the GMU bracket on ADHRS mount

Below is a pic of the Garmin bracket riveted to the the ADHRS mount. The Garmin bracket gets drilled/riveted to the ADHRS mount and the GMU-22 mounting ring gets drilled/riveted to the Garmin bracket. This could all probably be done through the wing root or access panel after the wings are closed up, although riveting the Garmin bracket to the ADHRS mount seem like it would be pretty tricky inside the wing. If it were me and I was trying to do this after the wing was closed up I would probably just mount the Garmin bracket directly to the access panel cover instead of the ADHRS mount.

2016-12-13%2015.49.45.jpg
 
James,

Scott would know better about release of the GMU22 mounting kit which I tested sometime ago. It makes the install and attachment to the wing bracket very easy.

Thanks Scott for chiming in.
 
I think the kit/plans mount the GMU brackets to the ADAHRS tray so that it can be slid into the mount in the wing making it easy to remove in the future if ever needed.
 
Let us know what you hear from Van's about availability.

I'm about to take all my big pieces to the airport and I'd like to get the magnetometer installed. I've been waiting for them to finish up the mount.
 
Vans says at least a few weeks before anything is released. Unless someone wants to come over and do my fiberglass parts for me I got plenty of other stuff to do while I wait.

Clay - sorry if the thread drifted too far. :eek:
 
What about strobes and landing lights..

..interference? Is the wing location out in the tip or in the outboard leading edge area? Anyone have a jpeg of the plans for this install location. I would assume it could be used for installation in an RV-10 as well, since the wings are so similar.
 
Magnetometer

Pardon my ignorance, but what is the need of a magnetometer? I am half way through my left wing build and noticed this conversation and it really caught my eye. I am tentatively planning on a Dynon panel, is there something I should install, while the bottom skin s still off?

Thanks,
 
This discussion is revolving around the Garmin Magnetometer for the G3x system.

I believe the magnetometer is built into the Dynon ADAHRS. If so, you are fine as the standard install is for the Dynon ADAHRS.
 
It's pretty easy to adapt the ADHRS mount in the left wing for the GMU-22. It's also fits nicely with the Van's wiring. The Garmin part you need is:

Garmin GMU-44 Universal Mount Kit P/N: 011-01779-01

You can find them on ebay brand new for pretty cheap. However I would recommend getting your hands on the GMU-22, or at least the mounting ring that comes with it prior to closing up the wing. The mounting ring (included with the GMU-22) needs to be riveted to the Garmin bracket, which is riveted to the ADHRS bracket. I can take some pictures of my install and send them to you if it would be helpful.

I am considering installing mine on a deck in the junction on F-01407 bulkhead and F-14131 fuse rib but this wing mounting option is very attractive. I wonder if the wingtip/landing lights cabling won't interfere with the proper operation of the GMU-22 since they run nearby and carry moderate and intermittent currents, like landing lights and led strobes.
 
I am considering installing mine on a deck in the junction on F-01407 bulkhead and F-14131 fuse rib but this wing mounting option is very attractive. I wonder if the wingtip/landing lights cabling won't interfere with the proper operation of the GMU-22 since they run nearby and carry moderate and intermittent currents, like landing lights and led strobes.

Ricardo, I had interference from the strobe initially. I was advised to make sure all wing lights were grounded back to the fuse which fixed the problem.
 
Next best location for mag mount ?

No
It is specific to a mount tray that gets built into the RV-14 wing during construction. Adding it afterwards would be difficult.

Looked, but do not find this addressed >>

My 14 wings are complete. Is there a recommended next best place to mount the Magnetometer than the ADHRS mount already in-place in the wing?
 
Take a look at this thread for alternate location

Search for "GMU22 Mount" on 9/16/2016. I'm not sure how to paste a thread link.:confused:
 
Rejuvenating this thread because....

I wonder if anyone has any issue with the lights or the pitot heat from a GMU22 in this wing location. I'm using the standard kit-supplied wiring. Should I expect any problems? I figure that if Van's supplies the wiring with the wing kit, and says to put the GMU22 on the bracket, all should be well. But?
 
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