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C55
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If you look on the Kadee website for the "under-track" permanent Magnets, or the paperwork that comes with them, there are diagrams of a hinged system to raise and lower the magnets, so they avoid the problem of passing axles and unwanted un-couplings. It's very simple and can be string/wire manual, servo, simple motor with pulley, operated - and cheap, too.

Julian
 

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C55
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2,549 Posts
Oh dear, a number of "it won't work" in the thread above....

Seep Uncoupler coils, and I suspect the RailCrew ones won't work with Kadee Couplers. At least, not installed the way the parts are expected to be used.


A Kadee (and the smaller N Microtrains) requires TWO magnetic poles at the track level, each positioned near each rail. Thus, the metal tail on one coupler is pulled towards one rail, and the tail on the other coupler pulled to the other rail.

The Seep (and similar) coils present a single magnetic pole at the track (pulling down) and the other is below the baseboard, pointing towards the floor. So, the effect on a Kadee is to pull both tails towards the centre of the track (and thus nothing happens).

The standard (and often expensive) Kadee coil is arranged so the poles are horizontal under the track, with two plates to bring the magnetic field up under the track - essentially just inside each running rail.
A Seep could be re-configured to work this way, but the coil has to be removed from the PCB, the metal pole piece shortened at one end, and two end shunts have to be fitted to bring the field up to the track (so it now looks like a Kadee coil).


The simplest cheap way I know to make controllable Kadee uncouplers is a small movable board (1 square inch, or thereabouts), with a number of rare-earth magnets glued to the board. Magnets arranged so the "N" poles are near one rail, and the "S" poles are near the other rail. This board is then moved under the track, and away again, possibly on a hinge, and moved by either a string, or a motor (a servo motor is one way).



- Nigel
There is a diagram that Kadee provide with their under rail magnets {308}. As Nigel mentioned, any suitable Rare Earth magnets, aligned with N under one track and S under the other can be hinged this way. The Kadee diagram is here
https://www.kadee.com/documents/308ins.pdf
I intend operating the string, they illustrate, by a small Servo, from a switch on the Mimic/control board. Simple, inexpensive and less to go wrong than electro-magnets.

Julian
 
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