Tip: Dynon Dual ADAHRS mount

[N427EF]

Just completed dual Dynon ADAHRS mount in my RV-10.
The following thoughts preceded the installation.
1. ADAHRS had to be mounted as far away from magnetic interference as
possible.
2. Mounting tray positioned accurately as per Dynon directive.
(within 1 degree of pitch and roll axis as well as parallel to the pitch axis)

3. Installation not to obstruct access to the tail section behind the baggage
compartment.

[N427EF]

1. There was really only one choice for placement of the ADAHRS.
2. I built a sturdy tray from left to right longeron and leveled it using the door
sill and seat back. Squared off 2 hardwood blocks to extend the angles to
the actual shelf. It seemed difficult to accurately measure a small shelf
all the way up on the roof.

[niblettda]

Very nice, I've not decided on Dynon or MGL, but I need a place to put the sensors and was planning the exact same thing. I'm just going to build a shelf there for any miscelaneous stuff like these sensors.

[plhamilton]

I am wondering why you used the door step and seat back in your alignment process. When I spoke to VANS recently, they indicated that the longerons should be 0 pitch.

Cheers. Paul.

Ps planning to do a similar mount for my twin dynons... Paul

[N427EF]

When I spoke to VANS recently, they indicated that the longerons should be 0 pitch.

That may be true in the RV-7 but for the the 10 Van explicitly instructs to use the door sill and the seat back as leveling surfaces.
Don't remember exactly but the longeron on the 10 was about 3 degrees off.

I

[paul330]

I have a very similar mount. I posted this a couple of years ago - are you sure you haven't stolen it?

Uploaded with ImageShack.com

I think this will very much be the de facto mount. It's simple, easy and away from potential interference.

The longerons are bent/twisted to shape the fuselage hence are not consistent. That's why the door sills/rear seat cross member are used as the datums.

[N427EF]

I have a very similar mount. I posted this a couple of years ago - are you sure yo u haven't stolen it

originally posted on 4-21-2010
Dang, and I was just about to file a patent application.

[plhamilton]

Originally Posted by N427EF

That may be true in the RV-7 but for the the 10 Van explicitly instructs to use the door sill and the seat back as leveling surfaces.
Don't remember exactly but the longeron on the 10 was about 3 degrees off.

I

Here is the email response I received from vans and my original question. I was originally planning to implement a platform on the longerons but i am now concerned that their accuracy while consistent may not be quite sufficient. I also have doubts about the clearance to the seatbelt mounts. I am therefore going to change my strategy and implement a similar platform to those depicted when I have completed fuselage attachment...

---------------------------


The longerons are the 0 pitch reference for the airplane so it's OK to mount
the AHRS to them. Typically builders put this a long way back in the tailcone
so the bridge is shorter (less susceptible to vibration)

Vans

Forwarded by: Support
Forwarded to: gusf
Date forwarded: Mon, 03 Jun 2013 08:06:04 -0700
Subject: Mounting dynon adahrs in the tailcone question
From: Paul Hamilton <plhamilt@hotmail.com>
Date sent: Sat, 1 Jun 2013 18:03:19 +1000
To: "support@vansaircraft.com"
<support@vansaircraft.com>

I am starting to work on the platform for my dynon adahrs to be
mounted in the tailcone of the RV-10. I looked at the AHRS platform
that you sell, but it does not meet the dynon requirements due to
the proximity of electrical components. I am thinking of building a
platform between the longerons but it needs to be within 1 degree of
parallel to all three axes. Are you able to confirm that the
longerons are indeed 0 pitch? If they are not, can you recommend a
location to mount the adahrs that would conform?

Cheers

Paul L Hamilton
Vans RV10 Builder 41387

[ppilotmike]

What kind of hardware do you use to prevent magnetic interference? Or is that even a concern?

[BonitaRV8]

The ADAHRS have magnetometers which are susceptible to Elector Magnetic Interference (EMI). The primary emitters of EMI are your radios, transponder and electric motors (especially brushed DC motors) which are used in the flap actuators and autopilot servos and electric gyros. The idea is to mount the units as far away as possible from those emitters; in reality the interference drops of with the square of the distance from the emitter so, once you are about a foot away, you should be ok. Try to keep them away from your antennas too. As far as what fasteners to use, I wouldn?t be too worried; the aluminum rivets will not cause any problems and, if you are worried, use stainless steel screws to bolt the units down.