Uncoupler magnets: Your experience?

Discussion in 'HO Scale Model Trains' started by Santa Fe Jack, May 7, 2007.

  1. Santa Fe Jack

    Santa Fe Jack Member

    Greetings, all.

    The recent coupler thread got me thinking about the under-roadbed magnets used to uncouple cars in a yard.

    Well - I'm just about the finish the yard on my layout. One more round of "pull the track up and put it back down", this time adding the power leads. So this is the last convenient time I have to make any modifications, which brings me around to these questions:

    Is it worth the effort to put magnets below the track
    in the yard to help with uncoupling cars?

    What is the best location for the magnets? Do they need to be at the entrance to each final lead, or could one serve at the entrance to a bunch of leads that splay out from there?

    Are there any preferred brands or configurations for the magnets? Could I get away with some toroidal (doughnut-shaped) magnets I have just lying around?

    Any caveats?

    Thanks for all advice. I guess I need to decide on this before laying the track down for the last time (barring any mechanical problems).
  2. Nomad

    Nomad Active Member

    I have been going through the same thing. I started out using a skewer, but pushed the little springs off the knuckles. Tried different magnets from the hardware store, but they were either to strong and caused false uncoupling, or to weak and did not work at all. I finally gave up and went with Kadee above the tie type, mainly because the track is already down. Honestly, I don't even notice them now unless I am switching.
    I tried putting a delayed magnet in the yard lead only, but found it was a lot better having one on each track in the yard. Say you wanted a car on the far end, you have to pull the whole string out to the magnet on the lead, uncouple,push back the cars you don't want, pull forward to get the car you want, push back, well you get the idea. A lot simpler with magnets on each yard track. If your switching a industry, you can get away with one delayed magnet.

  3. thedowneaster

    thedowneaster Brakeman

    I'm a bit of skeptic about the magnetic uncoupling. Having worked on the real trains, I know someone actually has to be there anyways to pull the pin up on the knuckle.

    I'm actually considering removing the little metal wire hooks from my couplers to help improve their appearence. Has anyone ever done this before? Can I simply use wire cutters?
  4. Nomad

    Nomad Active Member

    I have seen it done before. All that pin is for is magnetic uncoupling. That's what I was going to do. But them springs are hard to find !

  5. MasonJar

    MasonJar It's not rocket surgery

    Downeaster -

    Yes, it has been done with no ill effects (except of course that you can no longer uncouple with the magnets... ;)). And it does greatly improve the appearance in my opinion. Then you can add details like uncoupling levers and trainline hoses for an even better look.

  6. Gary S.

    Gary S. Senior Member

    I've said it before: Magnetic uncoupling R O C K S !

    Now, you do have to put in some effort to make the system work properly. Coupler height, rolling stock mods, draft boxes, graphite, electromagnets on mains, etc. It is all worth it in my opinion.

    Do a search on "magnets" here at The Gauge and I am certain you will find something.
  7. Gary S.

    Gary S. Senior Member

    Of course, you also realize that on real trains, a person is actually inside the cab of the engine too?:-D My point is, to say that magnetic uncoupling is unrealistic is being kind of picky considering all the other unrealistic things we do when running our trains. My 2 cents is that "hands-off" uncoupling adds to the enjoyment of running the railroad, at least for me.
  8. jeffrey-wimberl

    jeffrey-wimberl Active Member

    I use two undertrack magnets. One on a passing siding and the other on a stub-end siding. These work quite well, there's no cutting of ties needed and they're out of sight. If I desire to have a person there to "uncouple" the cars, I set a brakeman at trackside.
  9. Santa Fe Jack

    Santa Fe Jack Member

    I like the idea of the hidden, below-track magnets. And there's a certain appeal to electromagnets in this role as well.

    But it would be silly to buy a specialized under-track magnet when a simple off-the-shelf model would do. but how to judge the strength required? Perhaps just experimenting?

    Also - I like the idea of building my own electromagnets to go under the track. Again - has anyone here done this? What sort of arrangement of wire (wire diameter, coil diameter and length, etc.) did you use? This would be simply 12 VDC, right?

    Also - Kadee has two models of above-track magnets: a 312 and a 321, "nondelayed" and "delayed", repsectively. What is the difference? How can these magnets work differently?
  10. Dansco

    Dansco Member

    For the diff between the delayed and not delayed, the Kaydee website has a great little movie, that can explain it quick..

    I love magnets for uncoupling, I only have the above the ties kind, but have had little issue with them. I find that using magnets turns the activity of moving cars around, into something more like a game. It takes technique and prctice to do it smoothly... with delayed uncoupling, I love spoting cars by "trowing" them down a siding seeing how close I can get to the other cars/track end without actualy hitting them.. those who spot cars using magnets will know what I mean... I put this right up there with "DCC" for my personal enjoyment. If it wasnt for delayed uncoupling, I dont think I would be this far into this hobby.

    Thats my $0.02 (worth it too!)
  11. Russ Bellinis

    Russ Bellinis Active Member

    The only downside I've seen to under track magnets is if you get any hesitation as the locomotive pulls a cut out of a siding over the magnet you can get some nusence uncoupling. I've done operation on a modular layout where some modules have magnets and some don't and you have to use some other method of uncoupling. Other than problems if a train stalls over a magnet, I havn't seen any problems with under the table magnets, but uncoupling with uncoupling tools is not a problem for me either.
  12. Gary S.

    Gary S. Senior Member

    SFJack, I've done quite a bit of experimenting with uncoupling:

    As for "off the shelf" magnets - you may get them to work, but you need to do some serious experimenting before you finalize them on the layout. Make darn sure they work. They do require a certain strength and a certain orientation of the magnetic field crossing over the tracks to pull the metal coupler wires in opposite directions. I tried some different types, and was never satisfied. To me, the $4 each for Kadee under-the-track magnets was money well spent. Another option, you can actually cut/break these magnets in half, giving you 2 $2 magnets. Requires you to be a little more accurate with spotting couplers over the magnet, but may also lessen the problem of unwanted couplings too.

    As for the electromagnets, we had a good discussion on that awhile back. My determination was to use the O scale magnets that have double coils... yes, I use them on my HO scale layout (There are voltage and amperage parameters to be considered). The O scale electros are actually cheaper than the HO scale electros because the HO scale single coil comes with a bridge rectifier and a capacitor to make it stronger. The double coil setup has worked like a dream for me... am pleased as a hog in slop!

    If you want to discuss this in more detail, I would be happy to. I really love :-D this aspect of the hobby. I'll be without a computer for the next few days though.

    If you do a search on "electromagnets" you will find some good info.

  13. Gary S.

    Gary S. Senior Member

    Oh... must agree with Russ' post too. If you have sluggish and hesitating locos from dirty track and gunk, your uncoupling may certainly be disrupted = fRuStRaTioN:evil: .

    Answer = purchase good quality locos, keep them clean, and keep the track clean. Also, adding extra weight to locos that are not heavy enough is a good thing. I also found that weighting the cars to about 1.5 times the NMRA standards has made the unwanted uncoupling a thing of the past. There are ramifications and trade-offs to all of these suggestions. If you care to discuss further, let me know! As I said, I really enjoy the technical aspects involved in the subject, and I can talk your ears off if you let me!
  14. Gary S.

    Gary S. Senior Member

    Okay... one more thing... sorry about the multiple posts.

    This magnetic uncoupling stuff ain't cheap. It will cost you time and money to get into it and get it right. Right now I have 14 of the under-track permanent Kadees and 8 of the double coil electros, and will have another 10 or so perms and 6 or so electros on the other section that is still under design. Add in a 3 amp 24 volt power supply, some pushbuttons, and a time-delay circuit, and momma ain't happy about the credit card bill. But what the heck, you only get to run trains for a very short while as we hurtle through space on this little world we call planet earth.
  15. Santa Fe Jack

    Santa Fe Jack Member

    Dansco: Where is this little movie? I have not been able to find it on their web site. :confused:

    Gary S.: Thanks for all the information. As to cost, well, at this point it's sort of "in for a dime, in for a dollar". I've already spent too much on the 22 Shinohara turnouts, each with a Tortoise switch machine beneath. Adding a few magnets is just part of the game.

    So - I can really see the advantage of the electromagnets. No unintentional uncoupling would be the biggest advantage. On the other hand, I certainly don't need any more crowding on my control panel, which is already arguably overcrowded.

    The principal advantage to an undertrack magnet (as opposed to on the track) is aesthetic. It's hidden. The on-track magnet, however, can be installed later, and moved or removed, without having to tear up track.

    I'm glad I thought of this before laying down the track.

    Now - I still have to understand the delayed vs non-delayed distinction.
  16. Dansco

    Dansco Member

    Kadee® Quality Products Co. - Sample Prices

    this link has an animated jpg that shows exactly how the delayed action works.. in short, it allows you to "push" cars AFTER uncoupling, without recoupling.. (spoting). It can take a few minutes to load, even at broad band speeds..
  17. jeffrey-wimberl

    jeffrey-wimberl Active Member

    I've tried using other types of magnets (bar, rare earth, etc) most of these resulted in failure or at best, spotty performance.
  18. Santa Fe Jack

    Santa Fe Jack Member

    Excellent. Thanks for the link. So -- that's how I would expect these to work.

    So, then, what is "non-delayed" uncoupling?
  19. Dansco

    Dansco Member

    Thats a good question, I dont know :) Maybe the non-delayed magnets cant keep the knuckel open... I understand that you cant spot cars with the "non-delayed" magnets, but geeze, it seems that the ability to spot cars is more a function of the way the knuckels work than the magnets... hopefully someon with real knowledge will give us a clue!

  20. Nomad

    Nomad Active Member

    You are exatcly right. The non-delayed won't swing the coupler over, so when they seperate you recouple when you back up. The delayed magnets are wider, which pulls the coupler over. I don't even bother with the non-delayed. Delayed will work the same as the non-delayed.


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