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Wing Pin Reed Switches

Geico266

Well Known Member
Anyone have any luck getting these to work? Mine work, only when I have a stronger magnet next to them. I'm about ready to wire around them. The pins can be easily checked by the pilot prior to take off.
 
Care PKG

Just rec'd care pkg., so have not tried them yet, but thanks for the note. It'll be a while now until I get back to that. Still fiberglassing.

John Bender
 
Anyone have any luck getting these to work? Mine work, only when I have a stronger magnet next to them. I'm about ready to wire around them. The pins can be easily checked by the pilot prior to take off.

It took me more than four hours to get mine to work. I called Gus at Van's and he said that it was ok to enlarge the hole in the arm rest to allow the switch to get closer to the pin. I had to grind the hole so that I could get the switch higher. It was a real pain to get them to work. It seems to me that the steel tube is shielding the magnet. I think that the magnet is not strong enough or the switch is not sensitive enough. Perhaps if enough people complain about the difficulty, Van's will come up with a better solution.
 
It seems to me that the steel tube is shielding the magnet. I think that the magnet is not strong enough or the switch is not sensitive enough. Perhaps if enough people complain about the difficulty, Van's will come up with a better solution.

The magnet is just not strong enough when the reed switch is in the position called out in the print. I removed the magnet from the handle and it still will not work, unless you make the hole oblong.

From what I have read the engine will not start unless this ciruit is closed. Time for a work around.
 
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Hummmm,

Mabe I can help. Reed switches are made to be in the proximity of the magnet. Some have gaps of up to 3/4". If you have a reed switch that has a small gap then the only way around it is to use a rare earth magnet. These magnets can be purchased from any alarm dealer or supply house.

PS - Keep it away from your credit cards...!
 
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Thanks people

Since I was missing so many parts until today, I went on to the canopy. It is really nice seeing someone else blaze the trail. This MAY reduce my mistakes ( by at least one - - - - maybe ).

John Bender
Canopy trainee
 
Hummmm,

Mabe I can help. Reed switches are made to be in the proximity of the magnet. Some have gaps of up to 3/4". If you have a reed switch that has a small gap then the only way around it is to use a rare earth magnet. These magnets can be purchased from any alarm dealer or supply house.

PS - Keep it away from your credit cards...!

We will need a small cylindrical rare earth magnet, any ideas??
 
I talked to the Van's engineer (Ryan?) at SnF about the reed switches. The fix is coming soon, and is simple. I tried what he suggested and it worked.

1. Remove reed switches. Drill out the pilot hole in the arm rest to 1/4" with a narrow unitbit. Install the switches into the hole using the required clamp & screw. The head of the reed switch should prodrude through the arm rest about 1/4".

2. Test switch using a multimeter or 12v bulb.

3. If the switch still will not engage cut or grind off 1/32" of the top of the steel magnet barrel. This allows more "magnetic current" to escape the tube tripping the switch. Only take off 1/32" at a time until the switch works.

4. Test the switch to make sure it works.
 
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Radio Shack Aviation Hardware

The R/S reed switches supplied to us were inconsistent. One worked OK if it was close enough and the other did not work end-on no matter how we oriented it. We are using an alarm quality reed switch which is the same size but rectangular and it works perfectly if it is close enough to the pin magnet (as others have pointed out - that's hard to do).

Our "interim" solution was to use a longer screw and a 5/8" standoff on the DG clamp to get the switch position below the arm rest metal. With no metal in the way we positioned the switch closer to the pin magnet and it works perfectly now.

The downside is this puts the reed switch lower and closer to the pin and makes it more likely someone will disturb the switch while attaching or removing the wings.

The Vans solution looks better but I don't like the R/S switch quality and prefer the alarm company switches. I'd suggest trying a better switch before grinding the barrel.

- Neil

RV-6 (bought used - Dynonized the panel)
RV-12 (helping with electrons for a friend's kit)
 
A magnet is much more effective at closing a reed switch if the magnet and reed switch
are mounted parallel with each other, NOT perpendicular as originally designed. The picture
below came from the following website which describes how magnetic reed switches work.
https://www.explainthatstuff.com/howreedswitcheswork.html
The north pole of the magnet needs to be at one end of the reed switch and
the south pole needs to be at the other end of the reed switch. Polarity does not matter.
In lieu of relocating the reed switch, a piece of steel can be installed to
concentrate and direct the magnetic lines of force from the bottom end of the
magnet to the far end of the reed switch.

reed-switch-magnetic-circuit.jpg
 
Vans sells a kit to replace the magnetic switches with a mechanical push button type, that's what I did after several false warnings...
 
A few years ago I did some testing to characterize the spar pin magnet to switch activation distances on my RV-12. The interesting discovery was if the magnet is shielded too much by the stainless steel pin handle, switch activation could be inconsistent. Simply extending the guide slot to expose an additional 0.1" of the aluminum tube with the magnet in it significantly improved the activation reliability. The switch center distance above the end of the stainless steel section of the pin handle is also important and can be corrected by grinding a bit off the end of the pin handle. The attached pdf shows the area where the switch will activate relative to the installed positions for the original KAI dimensions and the modified version.

John Salak
RV-12 N896HS
 

Attachments

  • RV12 Spar Pin Magnetic Map w photo, Oct 2012.pdf
    477.9 KB · Views: 99
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