Cars not uncoupling at crest of the hump

[nkalanaga]

Bryan:  The axles I have certainly wouldn't be bothered by an uncoupling magnet.  Using a strong magnet, one designed for use on magnetic "white boards", I can pick up the wheelset by the point of the axle.  Trying to pick it up by the wheels, as it would normally be sitting, does nothing.  It just seemed odd that the axle would be very weakly magnetic, as most things I try are either obviously magnetic, or nonmagnetic.

[peteski]

As I mentioned earlier, some stainless steel alloys are weakly magnetic.

[videobruce]

I received my 1st set of magnets I ordered from China (a week earlier than the earliest estimate no less). I know I can't just place them between the rails without some type od adhesive,  but just what could I use that is removable? They are 10x5x2MM. I was thinking Wathers Goo.

[videobruce]

I tried these Neo magnets and they pull the couplers together no matter which way I placed the magnets. Instead of uncoupling they do the opposite. I tried taking  some pics but it doesn't show up as well as I would of liked.
Compare those w/ the 3rd attachment. MT's magnet works, these super magnets do not. I even stacked two and other then it was stronger (probably because of height) the 'trip pin' still gets pulled inward, not outward on both cars. (Those magnets were not secured down. When the trip pin came close enough the magnet lifted up to the pin.)

[nickelplate759]

your new magnets are too narrow, and look like they may also be off center.
Why not try @bbussey 's technique- put the magnets outside the rails (matched on each side of the track).   Then you don't have to worry about centering, or fitting, them between the rails?

I should add that I did try this on my last layout, and it worked like a charm.  As a bonus the magnets can be buried in the roadbed and hidden under the ballast.

[peteski]

Those rare-earth magnets are also very strong and should not be mounted over the ties, but under them.  Also the poles seem to be aligned end-to-end  on these. That would be wrong and will not work.  The poles need to be aligned parallel to the long sides.  That is very important for track center mounted magnets.

We had a discussion about this subject some time  ago. https://www.therailwire.net/forum/index.php?topic=34638 I recommend reading the info.

[bbussey]

@videobruce — I did post links to magnets that would accomplish the task. American company with great pricing and fast shipping. You should just order magnets from there.

[videobruce]

The magnets were just lying there as an initial test.
In my situation, magnets can only be between  the rails as they are now with a MT magnet, or outside the rails which I did try, but since they weren't glued down the test was meaningless. There is no under the table access since this (the crest) is up on a raised portion probably four inches above the table level which consists of 3/8" ply and 1/2" rigid foamboard.

I will look at that link when  I can.

[bbussey]

The MTL magnet can be removed, or the track segment can be cut out and replaced with a non-magnet-equipped section.

You should be able to bury magnets on either side of the track.  It's not a hardship to cut or carve a cavity into plywood if necessary.

[videobruce]

I temp placed two stacked magnets against the rail to see what happens, coupler never budged. Nothing!

[bbussey]

Your magnet surface isn't nearly large enough and, as Pete mentioned, orientation matters based on the pole locations.  Look at the photo I posted above.  I don't know how many times the solution must be reiterated before you accept it, but this will be the last time I do it.

[nkalanaga]

Why not uncouple them by hand?  That's what the prototype does!

[videobruce]

I've already tried different orientations, there is no change,
I'm waiting for the larger magnets, but i don't think they will do it either,
It's not as MT's magnet doesn't work at all, also I'm going to order another pair from  them since the 'half's I had somewhere, somehow disappeared on me. 

I appreciate the suggestions, but just because they work of others doesn't mean they will work for all. Some and just not piratical at the stage I'm at now. Six months ago maybe,  but not now. I never tested the uncoupling angle when I setup the class yard fully, I had many other things on my mind which is my fault. 

[wvgca]

Those rare-earth magnets are also very strong and should not be mounted over the ties, but under them.  Also the poles seem to be aligned end-to-end  on these. That would be wrong and will not work.  The poles need to be aligned parallel to the long sides.  That is very important for track center mounted magnets.

We had a discussion about this subject some time  ago. https://www.therailwire.net/forum/index.php?topic=34638 I recommend reading the info.

i ran rare earth magnets on my layout ... probably around two dozen places. the were 52 on strength. i ran the inside the track, at the furthest possible outer placement . they were aligned so the one end was positive, and the other end was negative.all were aligned the same,  they worked excellent.  they were placed between the ties, and the magnets highest point in a vertical placement.
they have worked excellent for seven years now [ Guests cannot view attachments ]

[bbussey]

I appreciate the suggestions, but just because they work of others doesn't mean they will work for all. Some and just not piratical at the stage I'm at now. Six months ago maybe,  but not now. I never tested the uncoupling angle when I setup the class yard fully, I had many other things on my mind which is my fault. 

Yeah, they will.

Pole location matters.  Orientation matters.  Based on your original photos, you have plenty of room for track-adjacent magnets regardless that the uncoupling location is on the hump.  Quarter-inch wide and one inch long with vertical poles would fit based on your first photo without any noticeable change to the terrain.

https://www.kjmagnetics.com/pdfs/BX042.pdf