[Twiddlydee]

I have an RV8 that has just failed a compass swing check and the cause has been found to be that the roll bar has become magnetic. Has this happened to anyone before? and does anyone know how to demagnetise it? Any help very very gratefully received!

 

[mlw450802]

I have an RV8 that has just failed a compass swing check and the cause has been found to be that the roll bar has become magnetic. Has this happened to anyone before? and does anyone know how to demagnetise it? Any help very very gratefully received!

I believe radioshack used to sell degaussers. I think they are simply an ac electromagnet that you place next to the part to be demagnetized and you slowly separate the degausser and the part and the magnetism is reduced.

I'm sure all you ex cub scouts remember how to magnetize a steel rod. Just hold the rod in a north/south (magnetic)orientation and smack it with a hammer (rivet gun). To demagnetize the rod, hold it in an east west orientation and smack it.

Good luck.
-mike

 

[Bruce_kwhp]

radio shack bulk demagnetizer

when I was a Nissan tech in the 80's the on board compass of the 280 and 300ZX would need the same thing done on rare occasion.

we used the radio shack bulk demagnetizer, a 110 volt thing you used like this.

starting at the center roof of the car you turned it on and made increasing circles (handing it to a helper) until you spiraled your way around the whole outside of the car, usually did the trick.

Bruce

 

[martin333]

I had the same problem with my RV8 6 years ago when I first started flying it. I tried everything - de gauzers etc , nothing worked. I then saw a new compass on the market called "SIRS". It was twice as expensive as most of the other compasses, but I was desparate, I needed a good compass that worked all of the time. I gave up and purchased the SIRS compass and have been happy ever since. It adjusts easily and is not bothered by the magnetic or electric or any other interference. Also, it has a dampener in it and doesn't bounce in turbulance.
Dick Martin
RV8 N233M

 

[Paul Eastham]

I was able to demagnitize my control stick using a radio shack degausser. Turn on degausser, apply to steel quickly, remove quickly, turn off. Repeat as necessary. For something larger like a roll bar, it may help to get a little compass to figure out where the problem areas are located.

You can get degaussers quite cheap on ebay, and I believe radio shack still sells them as well. Sacramento Sky Ranch apparently also rents a heavy-duty model for a heavy-duty sum.