# Securing KD magnets to track?



## noela (May 22, 2008)

I have a project to install the KD uncoupling magnets to track (not the under track versions, but the square ones that go over the ties). My question is this, how do I secure them on an outside layout that is prone to temperature changes and rain/snow? I would like them to be permanent, and was considering using Rubber Cement, Super Glue, Epoxy, etc., but am trying to find out from people that have dealt with this issue before.
Thank you.


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## Robert (Jan 2, 2008)

Mine came with a metal plate that went under the track, with the magnet on top of the ties. The magnet was strong enough that it stayed put for about 8 years in an outdoor deployment. I think when it finally shifted on me the problem was a major roadbed shift/failure rather than anything to do with the magnet/plate. 

Hope this is useful. 
Robert


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## Bob Pero (Jan 13, 2008)

Check the clearance when you put your magnets on your track. Some motor blocks hang lower than others and the magnet will catch and stop your locomotives. I cut out the ties and used Marine Goop to fasten mine to the track. I had these nagnets all over my layout becuase we ran "operations" once a month, and did a lot of switching.


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## noela (May 22, 2008)

Thank you. This particular job will not allow me to get under the track very easily, but I'll check it out.


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## noela (May 22, 2008)

Thank you. Any idea where to get this Marine Goop? Need it fairly quickly. If I use the KD gauge, should that be enough for clearance? Any idea which motor block will create the issues?
Thank you again.


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## chuck n (Jan 2, 2008)

I have used a blue putty like compound called FUN TACK. It holds quite well, but it is easily removed. It is available in most hardware stores and many supermarkets.

Chuck


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## Greg Elmassian (Jan 3, 2008)

"Amazing goop" has a number of variations, and it is available at home depot, squeeze tube... 

Pretty much a contact cement.. 










Greg


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## Jerry Barnes (Jan 2, 2008)

Chewing gum.


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## aceinspp (Jan 2, 2008)

I used Walthers Goo as you can remove if need be without damaging the mags. Later RJD


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## noela (May 22, 2008)

Needless to say, I really appreciate all of the suggestions. I have tried several of them, and sadly, I can't get them to work. The issue seems to be the correct height for the magnet, as well as dealing with the "plates". The "plates create an area of a gap that lessens the ability of the various methods to fully adhere to the ties. I am reluctant to cut away these plates, so I am again requesting help in how to deal with this issue. Also, should the magnet be flush with the top of the rail (this job involves Aristo Craft .332 Brass US Style Track and ties).
Thank you again for your help.


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## toddalin (Jan 4, 2008)

Posted By noela on 17 Aug 2012 08:13 AM 
Needless to say, I really appreciate all of the suggestions. I have tried several of them, and sadly, I can't get them to work. The issue seems to be the correct height for the magnet, as well as dealing with the "plates". The "plates create an area of a gap that lessens the ability of the various methods to fully adhere to the ties. I am reluctant to cut away these plates, so I am again requesting help in how to deal with this issue. Also, should the magnet be flush with the top of the rail (this job involves Aristo Craft .332 Brass US Style Track and ties).
Thank you again for your help. 


The "plates" are a real weak link in the outdoor environment. If subject to regular watering, they will rust away in no time. The magnets don't seem to rust.

If you use Crafter's Marine Goop, you should be able to secure the magnet directly to the ties. Use alot and let it encircle the ties because when it hardens, it will make a physical grip _around_ the tie and the actual adhesion to the ties themselves becomes relatively unimportant.

The top of the magnet should be just below the railhead such that a track cleaner block should be able to pass over it unimpeeded.


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## Bob Pero (Jan 13, 2008)

Marine Goop is available at Lowes or Home Depot


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## noela (May 22, 2008)

I'm sorry, I wasn't clear in my description. The plates that I am referring to are the cast plastic "plates" on the ties themselves. I used the "goop" and in my test it was excellent, but the gap created by the height difference between the top of the ties, and the top of the cast plastic plate left only a small area that was actually adhered to. I don't want to cut off those cast plastic plates as I think they may weaken the track and cause it to go out of gauge. I was thinking about building up the top of the tie so it would be at the same level as the top of the plastic cast plate, and was wondering if anybody else had tried this approach. Thank you for your understanding.


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## mgilger (Feb 22, 2008)

E6000 or Marine Goop is what you want. 

Mark

*http://mmg-garden-rr.webs.com/*


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## Greg Elmassian (Jan 3, 2008)

First, the magnets come with instructions on how high they should be.... you need to do what it takes to get it there. 

I'm a bit surprised at the comments that motor blocks hit them, since they are 

Which uncoupler are you using? The portable #844:










Or the "normal" one #842 that absolutely requires cutting ties:









Let's start with some "hard data".

Also, the uncoupler is BELOW the level of the rails... so if you have a motor block hitting it, then that's bad on the motor block, nothing is supposed to hang below the rail head, and you cannot go through a switch if this is true.

Greg


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## Jim Agnew (Jan 2, 2008)

If you use the KD gage to mount the magnet, the magnet will be approximately 1/64 above the railhead. I had to mill off about a 1/32 of the motor block cover on my USAT NW2 to clear the magnet.


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## noela (May 22, 2008)

Greg,
Thank you.

I have done everything I can to get the magnet below the rails and can't do it. I can't even get it flush with the rails. I am using the #844 w/.332 brass track, and it ends up about 1/64" above the rails. It doesn't seem to catch any of the couplers or motor blocks from several that I have tested, and the couplers work well. Any suggestions or thoughts?
Thank you again.


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## Greg Elmassian (Jan 3, 2008)

Yep, the 844, at least on Aristo track, forced me to mill down the surface of the ties such that the tops were cut completely off. 

Get a home router, and mill it down to get the proper height. You will have enough problems when it's the right height, it will be way more problems when it is 1/32" too high as it is now. 

After milling the ties, make sure it's the right height, using the Kadee #829 gauge. 

The biggest problem is not mounting the couplers securely or at the wrong height. After installation, the trip pin should be 1/8" above the rails. 

Jim: I will measure my Kadee gauge to see where it puts the magnet... I would think it is below the rails, but I see that Kadee has no document on the uncoupler height.... you use their coupler height gauge. 

Greg


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## Jim Agnew (Jan 2, 2008)

Greg, yes I use their height gage. You mentioned you have to mill the ties in order to mount the 844 magnet, did you mean the 842 magnet with the one piece steel backing plate?


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## Greg Elmassian (Jan 3, 2008)

Uhh... take a look at my post with the pictures... you have to mill the ties to mount the 844, and remove the ties for the 842... what I wrote is correct. I just double checked the kadee site again. My post shows pictures and part numbers and says what you have to cut. 

On my aristo track, I had to mill the ties down a bit to fit... actually, you can leave some of the ties for the 842 if I remember right, but more of the ties need to be cut away. The portable one the OP has (844) did not sit all the way down on my Aristo track, maybe it works right on LGB. 

In any case, you need to use the Kadee gauge to set the height of the magnet. I'm going to check again tonight and see where that places the magnet, but I'm pretty darn sure it is below the rails... but I could be wrong. Kadee does not spec this height and I searched all over the place. 

Greg


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## toddalin (Jan 4, 2008)

The 844 sits just above the railhead with LGB track so you would need to scrape the ties to get it lower.

OR if you just leave off the "H-plate" it sits below the railhead and you can Goop it to the ties. But make sure that there is still enough magnetism to active the couplers. Leave out the two iron bars for use outside because they will rust in short time. The top magnet has a bevel on one side to let it sit between the tie plate "spike heads."


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## noela (May 22, 2008)

Finally figured it out with the #844. Took some minor milling of ties, some scraping of the bottom magnet, and the use of "Goop" and Gorilla Super Glue, but it seems to be working, even after heavy rains. 
Thank you for all your help and suggestions.


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## Jim Agnew (Jan 2, 2008)

I've always wondered why the magnet was slightly above the railhead, so I sent the question to Sam Clarke at Kadee. Here's his response: 

Hello Mr. 

Because that's the correct height for our large scale uncoupling magnets. They may work OK mounted lower but we don't recommend it, the distance between the tip of the trip pin on the coupler head and the top of the uncoupling magnet is critical to top uncoupling performance. 

All of our between the rail uncouplers in all scales are mounted just above the top of the rail. 

Are you having some problems? 

Sam Clarke 
Kadee Quality Products


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## Greg Elmassian (Jan 3, 2008)

I haven't had the time to measure where the Kadee gauge puts the magnet yet, but if Sam says it's above the rails, then that's their goal. 

With only 1/8" clearance of the trip pin from the rail head, that's too close for me, and it just bothers me to have something above the rail head. 

I've had trip pins catch on the magnets at various times, the pressure on the couplers can cause them to deflect, and the problem is worse with truck mounted couplers and sprung trucks, as the coupler tang can deflect more. I've beveled the leading edges of the magnets and that has helped a lot. 

I've been looking into doing what people do in the smaller scales, use rare earth magnets, and fix them to a plate well below the rail head. There are people who sell kits for HO and I'm going to take that idea and scale it up to "G".


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## Dan Pierce (Jan 2, 2008)

Anyone try the magnet from a computer disk drive. These have mounting plates and holes for screwing them to the ties. 

Of course they are strong enough to make the sound magnets in the LGB engines trigger when you do not want them to do so.


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## Greg Elmassian (Jan 3, 2008)

A little more complex... the magnetic field is not just round spots... I'll get the link to the HO setup that works well... then you will see what is needed. Not too complex, just no one has done in yet in G. 

I did get to measure my Kadee gauge.... bottom line, the magnet is 1/64" above the rail head. 

Hard to see that this would make a big difference... I still do not like the height of the magnet exceeding the rail height... just not a good idea at all. 

A company called S & L Model Enterprises made/makes an HO kit:










4 rare earth magnets to product the "linear" magnetic field, probably need 6 for G scale... There's a trick to the orientation to make this happen. I'll see if I can find the "schematic".

Greg


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## toddalin (Jan 4, 2008)

N/S lie perpendicular to the direction of travel. Doesn't matter which side is which.


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## Greg Elmassian (Jan 3, 2008)

nope on the perpendicular... I'll find the stuff from the guy who made them, it's not what you would think.... 

here's another tidbit in the form of a sort of trick question: do you believe it makes a difference which pole attracts which "trip pin" outwards? 

not trying to be sneaky, but there some interesting information behind this. What do you think the answer is? 

Greg


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 22 Aug 2012 07:24 PM 
nope on the perpendicular... I'll find the stuff from the guy who made them, it's not what you would think.... 

here's another tidbit in the form of a sort of trick question: do you believe it makes a difference which pole attracts which "trip pin" outwards? 

not trying to be sneaky, but there some interesting information behind this. What do you think the answer is? 

Greg 



I think the answer is that you are wrong and it's not what you think.

And my track magnet and compass agree with me. And as to direction, my trains uncouple in either a clockwise or counterclockwise direction and this places the tangs on opposite sides where the effect would manifest itself.


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## Greg Elmassian (Jan 3, 2008)

Ahh, I said it was kind of a trick question! 

I always thought it was because the opposite poles, which you correctly demonstrate, but you did not answer the part I wanted to get to. It's ok because I would have had to give it away. 

The trick part is not because the trip pins are attracted to the "outside" but rather that the magnetic field will cause the 2 trip pins to REPEL each other. 

That's part of the puzzle. 

I talked to the guy to made the units I am talking about, and this was kind of a revelation. 

So that feeds into how you arrange the magnets if you use, for example, round rare earth magnets as the illustration shows. 

The arrangement of the magnets makes sense once it is explained. To summarize, in the drawing I showed, the 2 magnets on one side of the rails are NOT oriented in the same north south direction, but alternate. This also makes possible longer "fields" as long as you alternate them on each side. 

Alternating them is the only way to "extend" the linear field on one side. 

Greg


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 22 Aug 2012 08:56 PM 
Ahh, I said it was kind of a trick question! 

I always thought it was because the opposite poles, which you correctly demonstrate, but you did not answer the part I wanted to get to. It's ok because I would have had to give it away. 

The trick part is not because the trip pins are attracted to the "outside" but rather that the magnetic field will cause the 2 trip pins to REPEL each other. 

Greg 

Again, I think you are wrong. What you're saying probably has _some very minor effect_ when the knuckles are closed, but not after they start to open. 
Don't believe me? Just push a lone railcar with a Kadee over the magnet and watch the trip pin move to the outside. If it needed another trip pin of the same polarity next to it to do this, it shouldn't happen.


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## Greg Elmassian (Jan 3, 2008)

Yeah, I know, I did the same thing... 

Of course with one trip pin, there's nothing to repel from... so it proves nothing, there is no contest that the poles are on either side of the rails. 

And it is not inconsistent with what I have said. But you and I have clashed before, so go ahead.... 

You can be content to argue.... all I can tell you is this is from the person who SUCCESSFULLY built the HO and N scale devices that actually work. 

I was trying to be helpful to those who actually want to try and build one, and give them the information from someone who already built ones that work, and share the information that I gleaned. 

Obviously not appreciated.... OK, next time I won't speak up. 

Greg 

So, I respect the guy who got it working... and will believe him until I prove him otherwise


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 23 Aug 2012 03:38 PM 
Yeah, I know, I did the same thing... 

Of course with one trip pin, there's nothing to repel from... so it proves nothing, there is no contest that the poles are on either side of the rails. 

And it is not inconsistent with what I have said. But you and I have clashed before, so go ahead.... 

You can be content to argue.... all I can tell you is this is from the person who SUCCESSFULLY built the HO and N scale devices that actually work. 

I was trying to be helpful to those who actually want to try and build one, and give them the information from someone who already built ones that work, and share the information that I gleaned. 

Obviously not appreciated.... OK, next time I won't speak up. 

Greg 

So, I respect the guy who got it working... and will believe him until I prove him otherwise 

It proves you don't need a pin of similar polarity next to it to repel it to get it to move to the side.

I've got nothing against he way the guy did it with the button magnets and applaud his efforts. There is probably no easy way to simulate the elongated bar magnet using a bunch of "point sources." Nor do I have anything against you presenting it.

My only problem was that a) you said I was wrong when I described the direction of the "field" perpendicular to the direction of travel (which as I demonstrated it is), and b) the desemination of what my experiences and senses tells me is false information.


"Yeah, I know, I did the same thing..."

I think it goes back to the old Engineer/Scientist thing. Engineers work from what they've been told or read, whereas Scientists are more inclined to buck the establishment when their senses/data contradict it. How many countless times have you watched those trip pins move to the side when there was no pin next to it to repel it?


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## Greg Elmassian (Jan 3, 2008)

No, it does not, a single pin can be attracted to the edge of the magnet as you demonstrated. 

It does NOT prove that 2 pins are NOT repelled... 

You keep sticking on the single pin, and I already said at least 3 times now that it does not PROVE that 2 pins do not work by repulsion...

(and maybe the guy is right or wrong, but your experiment with one pin does not prove what you think it does) 

How many times in the above posts did I NOT contest you that a single pin would indeed be pulled outwards? I think THREE.

(yes I am repeating myself because you keep going over something that is not being contested at all, it just does not prove your point)


On a lighter point:

Remember the die hard movies, where the guy was giving them riddles? The trick questions?

And I did not say you were wrong, without the caveat that it was a "trick question"... instead of falling into the "spirit" of learning or hearing something different, possibly different than you are thinking, you took it personally.. 

Therefore, I am apparently a scientist and you are an engineer by your definition...










Greg


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 23 Aug 2012 06:25 PM 
No, it does not, a single pin can be attracted to the edge of the magnet *as you demonstrated*. 

It does NOT prove that 2 pins are NOT repelled... 

Greg 



Yes, as I've demonstrated.

If it is truly repulsion as you say, you should be able to put one magnet right under the center and both pins should pick up the same charge, regardless of the magnet's orientation, and repell each other jumping to the sides. There would be no need for the N/S poles at the sides at all.

The fact is that I've already been through this excercize and what I found is 180 degrees contrary to what you say. With a magnet directly under the center, the pins do not push out at all. In fact, just the opposite. If the pins touch, they are attracted and stick together.

I've not seen you demonstrate anything to prove your position.

Yippie Ki Yay


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## Greg Elmassian (Jan 3, 2008)

Nope, I have not demonstrated it, nor did you acknowledge this sentence: 

"(and maybe the guy is right or wrong, but your experiment with one pin does not prove what you think it does) " 

And of course no one is talking about a single magnet underneath. 

 I see what you did, the pictures support your position, the single pin test alone does not. 

It's a fine point that I was trying to make, and said it over and over... but it's ok... 

Yippie Ki Yay yourself (bad language is the last refuge of the ... fill in the blank... was wondering when you would descend to name calling)


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## toddalin (Jan 4, 2008)

Posted By Greg Elmassian on 24 Aug 2012 11:51 AM 
Nope, I have not demonstrated it, nor did you acknowledge this sentence: 

"(and maybe the guy is right or wrong, but your experiment with one pin does not prove what you think it does) " 

And of course no one is talking about a single magnet underneath. 

I see what you did, the pictures support your position, the single pin test alone does not. 

It's a fine point that I was trying to make, and said it over and over... but it's ok... 

Yippie Ki Yay yourself (bad language is the last refuge of the ... fill in the blank... was wondering when you would descend to name calling) 

I've not used any "bad language." I just referenced the same movie that you did. Yippie Ki Yay, simply means "Take that!" You seem to be inferring something into it that is just not there. But hey, if the shoe fits, who am I to argue?

_Res ipsa loquitur_

Have a piece of humble pie with Mr. Pons and Mr. Flieschman. I've proven my points through experiment and documentation, as a scientist would, while you've only proven that you can spout what you've read and can't follow through with your convictions.

That's all I'll say on this, unless you _prove_ me wrong, in which case I'll enjoy my humble pie.


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## Greg Elmassian (Jan 3, 2008)

The word after Yippie Ki Yay is what I am objecting to, do you think that everyone is stupid? Your last "who am I to argue" reinforces what I am saying. 

And another jab... "spout" 

I hope you feel better... 

You don't deserve any more helpful info, since you obviously know everything already... 

Greg


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