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RV7ator

Well Known Member
Garmin's G3X instructions show an RV7/9 installation in the rear deck. But this location violates most of the locating restrictions Garmin both requires (in one table) and recommends (in a second table). Vague, very vague.

For those of you with the GDU 44 in the aft deck, did you encounter any problems? Did you run the Magnetic Interference Survey?

For our G3Xpert, how much territory overreach can we drain out of the recommended/minimum distance tables? An RV isn't big enough to meet all and certainly not the highest priority disturbances.

John Siebold
 
The aft deck location worked out fine for us on the -3 John...passed the Survey just fine, and has not been a problem. You're right that to observe all the restrictions in the manual, it would have to be located on a boom a hundred feet from the airplane....

Paul
 
Thanks, Paul. Requirements creep and proximity-phobic are all too common. I envisioned letting it out on a HF antenna reel, with other gear on their own reels, sorta like "just married" cans.

John Siebold
 
GMU 44 Installation

John,

The GMU 44 magnetometer installation guidance provided in the G3X installation manual defines the ideal installation that will provide magnetometer performance almost guaranteed to be rock solid regardless of what is moved or powered within the plane.

While this type of installation can frequently be achieved on larger G1000 aircraft installing the GMU 44 in an outer wing section, it is seldom possible to achieve this type of installation in our smaller experimental aircraft.

The good news is that many have installed the GMU 44 in more convenient locations like the RV-7 aft deck and found the performance to be very acceptable.

Thanks,
Steve
 
While we are on the subject,

How about the GSU-73. Is the behind the panel an acceptable location. I saw a very clean installation that had it behind the GDU-37x on a custom made bracket. This made it very aces able With the GDU removed.
 
The GMU in the aft works fine...however we make a bracket that hangs it from the upper bulkhead 1 bulkead aft of the bagg compt and it worked out great for most of our customers. For the GSU, typical mount is indeed right behind the screen. That way it's really easy to get to!

Cheers,
Stein
 
Mark,

Section 4.6 of the G3X manual has few restrictions/requirements on locating the '73, all of which can be met with a behind-the-panel home. I'm putting it right behind the very shallow 370, short runs, weight forward, etc. That beast is heavy, so think about g's when you design your mount.

I'd certainly recommend putting a 3" muffin fan in the glare shield to suck out heat. I've done so on all the projects and you can feel it doing its job. Electronics don't like heat.

John Siebold
 
How Much, Stein?

That's where I locate Dynon's magnetometer. Perfectly happy there except when I got stupid and left the slider canopy open during calibration.

Do you sell your GMU bracket outright? Didn't see it right off on your site.

John
 
RV7ator said:
That's where I locate Dynon's magnetometer. Perfectly happy there except when I got stupid and left the slider canopy open during calibration.

Do you sell your GMU bracket outright? Didn't see it right off on your site.

John
Click to expand...

They aren't listed on the site and price depends on how much stuff you buy! :)

We try to keep them in stock for RV7 wingtip and fuse, as well as RV10 wingtip and fuse.

Cheers,
Stein
 
Stein,
Have you got a pre-made bracket for the Garmin GSU? Seems like a pretty common application.
 
MarkW said:
Stein,
Have you got a pre-made bracket for the Garmin GSU? Seems like a pretty common application.
Click to expand...

We do not, because most everyone physically locates things on the panel slightly differently, and then position the GSU accordingly. It's very simple to just make a shelf that goes from the main panel to the sub panle with some leftover stringer/longeron material - done correctly it'll be strong as heck, and yet easy to get to by simply popping out a screen whilst sitting in the seat. You don't want to just hang it off of the panel or the sub panel without making sure it's very solid....if it wiggles around then that won't be good!

Cheers,
Stein
 
Just a couple of notes about this. When I started planning my 900X installation for my RV-10, I was told that there was a requirement for a post-installation check before Garmin would approve any installation. There is no recommendation for location for the RV-10 other than the general guidelines, unlike other RV-models. An RV-10 located near me installed their 44 on the rear deck and, to pass the post-installation, ended up having to degauss the weldments in the tail and the rudder cables. I've elected to install mine in the wing, which still doesn't meet their guidelines, and hope for the best. The other day, in a conversation with Aerotronics, I was told that Garmin had dropped the requirement for the post-installation check for experimentals and that a simple operations check usually found no problems (the Garmin check is very rigorous in looking for magnetic interference). I won't know, of course, until I am in test a couple of years from now, but I am optimistic that it'll work just fine.
 
flion said:
Just a couple of notes about this. When I started planning my 900X installation for my RV-10, I was told that there was a requirement for a post-installation check before Garmin would approve any installation. There is no recommendation for location for the RV-10 other than the general guidelines, unlike other RV-models. An RV-10 located near me installed their 44 on the rear deck and, to pass the post-installation, ended up having to degauss the weldments in the tail and the rudder cables. I've elected to install mine in the wing, which still doesn't meet their guidelines, and hope for the best. The other day, in a conversation with Aerotronics, I was told that Garmin had dropped the requirement for the post-installation check for experimentals and that a simple operations check usually found no problems (the Garmin check is very rigorous in looking for magnetic interference). I won't know, of course, until I am in test a couple of years from now, but I am optimistic that it'll work just fine.
Click to expand...

This is sort of correct...the "post install check" has never been required for the G3X system though - it's been that way since day one with that product (even though it uses the GMU), it has a very good calibration sequence in the manual and on the screens of the 3X. The aft deck location is particularly poor with the RV-10 due to the trim system back there, but not nearly as big of an issue with the rest of the fleet which has shown a pretty good success with installs in that location. That of course assumes you have no ELT or strobe power suppoy (or other electrical device) sharing the same shelf. We still prefer the wingtip or mid fuselage location if possible and aft deck as acceptable as long as it's not an RV-10. Completely different animals/aiframes between the 2 seaters and the 10.

Below is a quick pic of a typical fuselage mount.

Cheers,
Stein

GMU44%2520Mount%25201.JPG
 
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The reason I prefer the fuselage over the wings is that you can do your testing earlier - like at home, in the workshop, long before you take the airplane to the airport and put the wings on. that way, if you have issues/problems, you can solve them far earlier, and not leave it until those frantic times when you are trying to get to first flight. I have seen a number of airplanes flying with useless EFIS's because the builder couldn't' get something working, and he was so close to flying that he just went without it being fixed...and that is sad.
 
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