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Degaussing

TShort

Well Known Member
I've got the magnetometer for the G3X mounted aft in the tailcone

Today while doing the interference testing it failed massively with minimal rudder movement. Like >500%

Garmin says I need to degauss the rudder cables.

Has anyone done this? What is the best way to do so?
 
People often test for ferrous metal with a magnet, which then magnetizes the metal.
 
Another potential interference source is the rear seat shoulder harness cables.

A simple backpacking compass can be used to test for unwanted magnetic fields.
 
Been there done that... I have 2 degausers now because of an RV4, I had to buy the "big bertha" model for the RV4. After spending a bunch of $$ for the big one (weighs about 25 lbs) and having marginal success I finally gave up and put the magnetometer in the wing, problem solved (or at least I finally was able to get it to pass).

I think the wost offender was actually the trim cable and it was a lot easer to relocate the mag than RR the cable to degauss it. I had to call on my weightlifter friend to crawl in the back and I passed him the degausser and he did his best but still failed.

I still had to degauss the wing/aileron/hinge hardware though :eek:
I was sweating it for a while as the gear legs were also magnetized and I worked on them for hours.
 
It has to be the rudder cables; it passes just fine until I move the rudder, and then the thing goes nuts.

We have some leeway (slack) in terms of moving it up, but relocating to the wing would be a nightmare with the CAN bus, etc...
 
Degauss tool

I've heard a gun type soldering iron works it have not tried it yet. Basically pass the cable through the space between the solder point loop, pull trigger and slide it along the cable slowly.
 
I've heard a gun type soldering iron works it have not tried it yet. Basically pass the cable through the space between the solder point loop, pull trigger and slide it along the cable slowly.

I saw that somewhere too ... stopped and got one on the way home from the airport just now.

Will report back...
 
Whatever you use, be sure to power it up prior to getting it close to the material. Move it slowly closer, continuing varying movements (circular works), and continue those movements until well away from the material. Only then power it down. Power-up and power-down causes large current/magnetic field excursions, which can re-magnetize your material.

Charlie
 
My shoulder harness cables became magnitized. Had some success using the soldering iron method.
 
Whatever you use, be sure to power it up prior to getting it close to the material. Move it slowly closer, continuing varying movements (circular works), and continue those movements until well away from the material. Only then power it down. Power-up and power-down causes large current/magnetic field excursions, which can re-magnetize your material.

Charlie

Interesting.

I thought the rudder cable needed to go down the middle, between the two legs of the soldering gun. Does it just need to be near?

Perhaps something like this might work?


https://frys.com/search?search_type=regular&sqxts=1&cat=&query_string=degauss&nearbyStoreName=false


Also - I will definitely pull the magnetometer out before I do this. Do I need to pull other stuff - GSA28 servos, transponder, etc - that is mounted aft?

Thanks
 
Solder gun

That's where the field is. You can also make a bigger loop with #12 Rolex. Strip a piece and insert the ends in the solder gun screw clamps.
 
Go find an an old bulk magnetic tape eraser. This works well. I used it to degaus the roll bar on and RV-8.

Carl

This is what I used, an old Realistic tape eraser, used by my 10-friend too. Did shoulder harness cables, rudder cables and elevator horns. Some were more difficult than others. There are instructions for it . . . some where on the internet too.

$15
 
The Thorsen coil linked earlier is simply multiple turns of heavy gauge 'magnet' wire (enamel insulation), wrapped with tape, with an in-line on-off switch. The original use was degaussing picture tubes (CRT). Normal use is to hold the coil flat, parallel to the face of the CRT, moving it in a spiraling circular motion. (Plenty of utube videos on how to use one.)The field is strongest closest to the coil; its strength drops rapidly as you move away, just like a regular magnet.

The bulk tape eraser would be my 1st choice, if available, but the methods I described are still important, to avoid re-magnetizing the material.

Charlie
 
Realistic - that is the one.


Yep 44-232 like my link above. I inherited one and sat on my self for a while until my 10 friend said he had an inflight magnetometer error.

Use a pocket magnetic compass to wave over the part and see it is magnetized, then put it on a wood or plastic table and wave the tool in a circular motion over the top 5-8", working down to the end of a cable. Continue the circular motion while with drawing the tool to about 3 feet then turn it off. Recheck the part with the compass.

I took my rudder cables and pulled out about 3 feet to do them in free air. The stretching and swaging process imparts some magnetism.

Get some instructions for the tool as it has a limited duty cycle.
 
Thanks.
I'm gonna try the soldering gun first, as I have one of those.
Hopefully I will be able to do it in place.

I also found (based on a suggestion from the aeroelectric list) a phone app that accesses the magnetometer in the iphone. Messing around here at the house with magnets, etc it seems to be pretty sensitive.
 
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