Using neodymium magnets between the sleepers

The Kadee 308 magnet and keeper plate is too thick to allow it to be sunk into the cork track bed. I would also need to cut away some of the MDF baseboard top to recess it fully. This is quite a lot of unneccesary extra work.

I have also tried the Kadee 321 Between-the-rails uncoupling magnets. I find these rather unsightly and rather expensive.

I have now obtained via eBay a quantity of 6mm diameter x 3mm thick neodymium magnets. I got 50 of these for less than the price of either of the Kadee products.

I bored some 6mm holes in some scrap cork track bed material at various spacings and pressed the magnets into the holes before laying some scrap track over the top.

After several tries, I started to get fairly consistent results using a pair of magnets each side of the track centre line, spaced 12mm apart. Each pair was spaced 8mm apart. All measurements are taken from the centres of the magnets.

Here is rough sketch of how they will be installed:



Once ballasted they should be undetectable - except by the couplings!

Further tests are still to be conducted, so this plan may yet be modified.

Perry

Tried something similar myself a few years ago following guidance from someone on RMweb. Only two magnets were used, one each side, offset from each other - diagonally opposite ones in your diagram - each to the right hand side of the couplings looking out along the track from the coach/wagon. These provided sufficient attraction to the two offset Kadee tails.

Thanks. That's encouraging, Geoff. I'm still going to do a bit more experimenting before I decide whether to go with the neodymiums or not.

Perry

Although I persevered for a while with the neos in one siding, I eventually decided that the positioning of wagons was too sensitive - too short and precise - compared to the Kadee magnets. I have now fitted a number of the Kadee under track magnets. I use a cork underlay and then a soft sticky roadbed and together they give enough height to the track to allow an under track magnet with ease.

I shall watch your progress with interest, though.

Yesterday, I saw a demonstration on UK stock - Kadee's fitted & rare earth magnets similar in the method Geoff describes & worked very well indeed.

I have tried using magnets to serve a couple of sidings as the Kadee literature suggests & find them wanting. Even to have one magnet serving a siding that has two or more drop off points. If one shunts into the siding a train of 6 wagons & the furthest 2 from the loco are the ones to be dropped, using the Kadee shuffle, these two can be set to delay, push them to where you want them & in some cases, you may find, other wagons that still have to remain connected to the loco, now sit over the magnet & of course , when pulling away, they become uncoupled again.

[user=422]Geoff R[/user] wrote:

………….I eventually decided that the positioning of wagons was too sensitive - too short and precise - compared to the Kadee magnets………….

That's why I'm tryng the magnets in two's either side of the track; it should give a longer uncoupling position.

Unfortunately, my cork trackbed is already down and the point motor pins have been cut to length, so there not much chance of me putting a thicker bed in. :???:

I'll persevere with the neo's for a while and see how I get on.

Perry

[user=95]Sol[/user] wrote:

Yesterday, I saw a demonstration on UK stock - Ksdee's fitted & rare earth magnets similar in the method Geoff describes & worked very well indeed.

I have tried using magnets to serve a couple of sidings as the Kadee literature suggests & find them wanting. Even to have one magnet serving a siding that has two or more drop off points. If one shunts into the siding a train of 6 wagons & the furthest 2 from the loco are the ones to be dropped, using the Kadee shuffle, these two can be set to delay, push them to where you want them & in some cases, you may find, other wagons that still have to remain connected to the loco, now sit over the magnet & of course , when pulling away, they become uncoupled again.

………..Therefore a 'shorter' uncoupling location could be an advantage. :thumbs

At the moment I'm still finding my way around the Kadee couplings. I've managed to mangle - and replace - a couple of the little springs so far…..:roll::shock:

Perry

Thinking about the round magnets that I already have, the poles are on the opposing flat surfaces. This means that, when laid flat, the magnetic force is trying to pull the pins on the Kadees downwards, rather than sideways. If one observes the couplings being moved across a Kadee magnet, the force is quite obviously lateral, not vertical. It is very difficult to fix the round magnets on edge. If they are set on edge below the bottom of the sleepers, i.e. embedded in the trackbed, there is virtually no 'pull' on the Kadee pins. I tried holding a round magnet with the flat surface vertical alongside the outside of the rail and pushed a truck past it. The action on the Kadee was very positive, far more so than when the magnet was laying flat.

I have therefore ordered some 3mm x 3mm x 3mm neodymium cubes. These can obviously be oriented to provide a lateral pull and still have a flat surface by which they can be fixed in position. I intend trying them set against the outside of the rail, but between the sleepers.

They should be delivered around the middle of the coming week. :thumbs

Perry

That sounds promising, Perry.  :thumbs

[user=269]MaxSouthOz[/user] wrote:

That sounds promising, Perry.  :thumbs

I hope so, Max.

At this rate I'll be setting up as a wholesale supplier of spare magnets! :shock:

This will be the fourth batch I've bought, but I guess Research and Development is never cheap.

Perry

yes  kadee magnets have the poles along the sides, i tried the neo type all they did was pull the stock downwards,
so I finished cutting the kadee ones in 4 bits which gave me small magnets at the station for uncoupling the loco,
works quite well too.
lol::cool:

[user=15]owen69[/user] wrote:

yes  kadee magnets have the poles along the sides, i tried the neo type all they did was pull the stock downwards,
so I finished cutting the kadee ones in 4 bits which gave me small magnets at the station for uncoupling the loco,
works quite well too.
lol::cool:

The direction of the magnetic 'pull' seems very important. I'm hoping that I can sort that out with the cube-shaped neo's.

I take it that it was one of the big, Kadee 2" magnets, that you cut up? What did you cut it with, and do you still use a metal ground plate with the four pieces?


Perry

it was a between the rails type, I used a junior hacksaw and cut across the magnet they still have the poles along the sides

Thanks, Owen. :thumbs

Perry

I've just received notification that my new neodymium magnets have been despatched today. :doublethumb I'm really looking forward to being able to get on with sorting the uncoupling out.

Perry

The 3mm cube neodymium magnets have arrived.:thumbs

I tried single ones outside the rails but got no movement from the couplers whatsoever. I tried various configurations and combinations and have so far discovered that putting two rows of five magnets between adjacent pairs of sleepers gives an excellent positive uncoupling response. What concerned me then was the possibility that the magnets may have been touching both rails and therefore causing a short circuit.

I laid some magnets up between the sleepers on a short section of track on some double-sided adhesive tape to stop them lifting out of place and checked across the rails with a multimeter. As least on the check I carried out there was no short circuit. I think it will be as well to check each installation as I do it. I have sufficient magnets to supply five uncoupling locations - by chance, exactly the number I need for the layout. :thumbs

Before I fix them all in place permanently, I will do a little more experimenting but I don't really expect to come up with a better solution.

The total cost of the neodydmium magnets was £3.49, which as I said before, will equip five uncoupling locations. This compares very favourably with the Kadee under-track magnets at £3.75 each or the Kadee between-the-rails magnets at £4.75 a pair.

Please note: the above observations apply to Peco Code 100 Streamline track. I cannot vouch for the effects of using these magnets on any other track.

Once I have some magnets properly installed on the layout, I will take some photos and possible a short video to show the uncouplers working.

Perry

I am watching this for sure as I am a Kadee user.

I know I probably don't have to say this to a modeller of your experience, Perry BUT, I forgot that for Kadees to work needs a STRAIGHT track.  Not just where the magnets are, but for at least the length of a car either side.

I made these beautiful flowing curves on my RR&Co shelf layout and there was only ONE place I could find which was a long enough straight.  Even then I had to use short wagons and loco.

Like I say, I know I probably don't have to say it - or do I quest:

 

It's OK, Max. I had done my homework! :thumbs

After a bit more testing, I decided that the two transverse rows of five magnets for each uncoupler was the way to go.

I lifted the appropriate sections of track so that I could remove the  flat ceramic magnets I had installed initially. I infilled the magnet  slots with pieces of scrap cork tile.

This also allowed me to put down some really strong double sided  adhesive tape on the trackbed. The magnets could simply have been glued  in place from above, but as the track was up anyway I thought this was a  good plan to see how it all works out. If the magnets lift from the  tape in the future, or I decide that I want to move the location of an  uncoupler, it will be easy enough to pull them out and glue them into  their new locations.

Here are a couple of shots of the magnets in situ:





They are a snug fit between the plastic track side members and don't  touch the rails themselves. If they did, it would cause a short circuit. I check each installation as I go with a multimeter, just to be safe.

No problem has been found (yet!) with wheel flanges or anything else  catching the magnets. They sit too low for that to happen, it appears.

I set up a 'test bed' on a scrap of MDF with a piece of double-sided  tape and some scrap track on it and put each of the two rows of magnets  onto that to ensure I had them the right way round. I did it by rolling a  wagon past the magnets to check the direction of deflection of the pins  was correct, then lifted them straight out, one row at a time, and  slotted them into the prepared places on the layout.

This whole job takes only a few minutes. It took me a little longer as I  had to lift and relay some track, but normally the magnets could be  superglued or araldited in very quickly.

Here then, is this years Oscar nomination:

http://www.youtube.com/watch?v=1N2q_6PFuzc

Neat and cheap, huh? :doublethumb

Perry

[user=95]Sol[/user] wrote:

I am watching this for sure as I am a Kadee user.

I'm guessing that it might even be possible to scrape enough ballast out of the way to retro-fit these onto an existing layout.

Perry