Sparky

Sparky

Well Known Member
I see that Van's now sells a new AHRS mount kit for the RV7 & RV9. Here's the link: http://www.vansaircraft.com/cgi-bin...83058746-316-84&browse=new&product=AHRS-mount

The new kit installs the AHRS (I assume the magnetometer) for Garmin G900X or Grand Rapids Technologies (GRT) near the bottom rear fuselage skin just forward of the F707 (for the RV7) bulkhead and aft of the baggage (F706) bulkhead. I am installing a TruTrak pitch servo and it looks like the proximity of the ferrous materials in the servo assembly may not be compatible with this AHRS mount for my GRT magnetometer. Any thoughts?
 
Sparky said:
I see that Van's now sells a new AHRS mount kit for the RV7 & RV9. Here's the link: http://www.vansaircraft.com/cgi-bin...83058746-316-84&browse=new&product=AHRS-mount

The new kit installs the AHRS (I assume the magnetometer) for Garmin G900X or Grand Rapids Technologies (GRT) near the bottom rear fuselage skin just forward of the F707 (for the RV7) bulkhead and aft of the baggage (F706) bulkhead. I am installing a TruTrak pitch servo and it looks like the proximity of the ferrous materials in the servo assembly may not be compatible with this AHRS mount for my GRT magnetometer. Any thoughts?
Click to expand...
The GRT AHRS and magnetometer are separate. Mount the AHRS on this mount and then mount the magnetometer elsewhere, like in the wing or further back in the tail.

GRT AHRS
AHRS3.jpg


Dual AHRS
AHRS_D_001_MED.jpg
 
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More info

Correct, they are two different boxes. I chose to mount the AHRS forward of the panel under the forwardmost top skin. Just run a piece of angle on the lower flanges and between the ribs that run fore-aft back from the firewall. Mount the AHRS front on the firewall top horizontal angle and the rear will be perfecly level on your angle that's under the ribs. This keeps the wiring forward of the spar.
picture
Van's, in my opinion, makes running wires a problem with inadequately sized holes and when you call about enlarging them they won't give solid advice because they haven't tested it.

As for the magnetometer, I mounted that on the flat deck just forward of the HS spar and aligned it 90 deg. (square) to that spar. That takes care of the critical alignment that GRT wants in all three directions. It is said to be sufficiently weather proof to be ok in this location under the intersection fairing.
picture.
 
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Revisiting an old post...

Is the Garmin 900X AHRS and Magnometer also split in 2 units?

I want to mount my Skyview AHARS and this is a convenient space, but the Pitch Servo and The RV10 rear battery and contactor in the vicinity has me worried about the magnometer in the Skyview ADAHRS.

Anyone confirm about Garmin 900X split, or skyview in this area.
 
Rudi, the Garmin AHRS and magnetometer are separate. This location is fine for the G900X AHRS. Garmin currently does not give specifics of an RV-10 magnetometer installation despite several flying (and therefore Garmin certified) installations. Going by their guidelines, the unit would have to be flying formation with the airframe, because they want 3 feet from ferrous materials or power-carrying wires and six feet from any motors. However, I am told by at least one other -10 builder whose aircraft is equipped similarly to mine that their installation of the magnetometer at the rear fuselage deck between the HS spars worked fine and was Garmin certified despite the proximity of trim motors, tail strobe, and elevator horns.

Sorry, I have no information on the Skyview. Pierre, the magnetometer in my BMA system was designed to be aligned as close as possible to level in cruise. For RVs, this meant installing level with the fuselage longerons and then doing a software level setting in flight. The Garmin unit is also intended to be leveled relative to the aircraft, not the panel.
 
For my GRT system, my foggy memory is that the AHRS needs to be aligned fore and aft with the direction of flight and the magnetometer be as close to the same alignement as the AHRS. Differences in the alignement between the two results in a magnetic heading that is an "amplified" amount off.

Although I may be misremembering things from LONG ago:eek:

Jeremy Constant
RV7A100hrs
 
Update, for future reference...Putting the Dynon Magnemeter here is not a good idea if you are going to fit a AP Servo. Those magnets is the Servo's cause Havoc. You need to be at least 2 ft away for a normal magnetic compass not to sway in the tailcone. I tested and need to make another plan
 
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