ADAHRS mounting location in an 8

Updating panel to glass and wondering where people have mounted their ADAHRS box in an 8.

Search didn't provide much, except one person mounted it on the left wing inboard inspection panel.

Thanks.

Good timing!

I just asked this question of Van's Support less than a month ago. Here was the reply:


My plan is the end of the mid longerons, midway between the bulkheads. Lots of people mount it on the upper longerons, but that's a pretty important structural part and was unsure. So I asked Van's! The mid longerons will also prove easier to work on since that location isn't so tight against the upper fuselage skin.

Upper longerons

Here's where I installed mine. On the top longerons.

The mid longerons would interfere with the elevator pushrod while the lower longerons might interfere with the rudder cables.

Don't forget to avoid ferrous hardware. I used brass screws & nuts.

I mounted my Dynon ADHRS on the inboard inspection panel of my LH wing. I used aluminum shims and brass screws to level it to be fuselage. After 640 hrs of operation, it has worked perfectly. I did discuss the installation with Dynon back in 2014 and we could not find any technical or safety issues with putting it there. AOA and pitot lines are a short run, the network cable is a short run through the LH side of the spar up to the panel area. Also have a the same installation in a 9A and it has also worked fine for 350 hrs. For water proofing the inspection panel, I put a thin layer of RTV on inspection panel mating surface and let it dry before installation.

I mounted mine at the rear-battery location. Since the location is close to the pitch servo and the rear baggage compartment, it ADHARS magnetic deviation will be affected by metals around it. I had to purchase a separate magnetometer which is mounted at the wingtip, away from most ferrous metals.

You didn't say which manuf you are using, if it's Garmin it can go on the sub-panel which is very convenient.

riseric said:

Here's where I installed mine. On the top longerons.

The mid longerons would interfere with the elevator pushrod while the lower longerons might interfere with the rudder cables.

Don't forget to avoid ferrous hardware. I used brass screws & nuts.

Click to expand...

Installed mine the same place. Seems to work fine.

Oliver

I used a piece of scrap honeycomb 1/4” fiberglass board (from a neighbor’s Lancair 4 build) and a couple of pieces of light J channel (left over from the RV-10 build).

Use a Dremel tool to remove the honeycomb around all the edges about 1/2” deep under the glass. On the long sides use micro in this hollow edge to attach the angle. On the short sides just use micro. The micro gives you a solid core for the attach screws.

Note - adding the angle is likely overkill for this application.

I originally planned to mount the board on top of the longerons. After I fitted the top skin I realized I could not get the board in and out with the skin on. I shortened the board to fit on the bottom side of the longerons. I used four #8 SS screws and SS Nyloc to attach to the longerons and nylon hardware to attach the modules to the board.

Compass cal results were excellent.

Carl

ADAHRS in an 8

Thanks for the responses.

Will be forging ahead in the next few days and considering the options. Looking at the wing inspection panel or just aft of the aft baggage compartment as the most likely options. Adding a Dynon AOA pitot at the same time, so left wing is looking like a good candidate.

It's a Dynon unit so needs to be remote from magnetic influence.

Will try to remember to take some pictures.

Thanks again.