Microtrains-kato Turn derailments

salamander34 Feb 11, 2020

  1. BNSF FAN

    BNSF FAN TrainBoard Supporter

    6,825
    10,812
    118
    I'm guessing replacing locomotives is out of the question so you could try the M/T 1037 Barber roller bearing medium shank truck with coupler first and if that doesn't work, then try the M/T 1038 Barber roller bearing long shank truck with coupler. If either of those doesn't work, drop back and punt.
     
    EsK likes this.
  2. EsK

    EsK TrainBoard Member

    60
    19
    4
    Being a relatively inexperienced modeler, I went by BLI recommendation on the locomotive specification sheet and included a few 9-3/4" curves on the layout because I was tight on space. I then ran the locomotives at good speed on the curves & turnouts & they worked well, so went ahead and completed the layout. Only after completing it did I hook up the freight cars, only to realize my blunder!

    Can't change the layout now and can't return all the locomotives (they run really well too!). Though not a stickler for prototypical looks or running, do appreciate all the information that you provided, really interesting.

    Coming back to the problem at hand, I think my only option is to do something with the couplers. Would appreciate all guidance on it.

    Thanks,
    Krish
     
    BNSF FAN likes this.
  3. EsK

    EsK TrainBoard Member

    60
    19
    4
    Will order these right away & try, thank you!
    Best,
    Krish
     
    BNSF FAN likes this.
  4. ns737

    ns737 TrainBoard Supporter

    670
    103
    23
    take a micro-trains 40' box car or a 50' gondola and make one end a body mount. if you feel you can not do it send me the car and I can do it for you.
     
    EsK likes this.
  5. ns737

    ns737 TrainBoard Supporter

    670
    103
    23
    I made 4 cars that way. so it is not always the same car up front.
     
  6. EsK

    EsK TrainBoard Member

    60
    19
    4
    Thanks! Could you please send me a pic of one of the cars for me to understand. If I think I cannot do it, might take you up on that offer :). What part of the country are you at, I am in Northern Virginia.

    By the way, does it necessarily have to be body mount couplers? Per BNSF Fan's suggestion to try Micro-Trains N 00302044 (1038) Barber Roller Bearing Trucks with Long Extension Couplers, four trucks are going to be cheaper than 4 cars!
    Just asking :unsure:


    Best,
    Krish
     
    Last edited: Nov 13, 2020
  7. ns737

    ns737 TrainBoard Supporter

    670
    103
    23
    for me the only thing that worked was the body mount. all i run is kato unitrack. I will try to get a pic up tonight. right now I am getting ready for setup at a train show. as far as the cars go. use a car you have.
     
    BNSF FAN likes this.
  8. EsK

    EsK TrainBoard Member

    60
    19
    4
    Would appreciate it if you could please also let me know the Micro-Trains part number for the body mount coupler. Will order a set of those as well and will attempt to install them based on the pic you send.

    Guess you are a participant at the train show, all the best & have fun.

    Thanks again,
    Krish
     
  9. BigJake

    BigJake TrainBoard Member

    305
    226
    10
    This.

    Any time you can ease the transition between different radius curves (consider that straight track has an infinite radius of curvature), it will improve operation and appearance. I run Kato long chassis, 6 wheel locos on a few 9.75" radius curves, but I don't transition from straight directly to them!

    I use a formula to evaluate the severity of the transition between different radii (including S curves), as compared to an equivalently severe transition between straight and curve with radius Requiv:

    Requiv = 1/(1/R1 - 1/R2) for same direction curves​

    A variant of this formula also works for S curves, if you add rather than subtract the two reciprocal radii:

    Requiv = 1/(1/R1 + 1/R2) for different direction curves.​

    In other words, the sign of a reversed-direction radius is treated as negative.

    Interestingly, when you consider and S curve with two back-back 19" radius curves (or #4 switches), the equivalent severity transition from straight is to a 9.5" radius curve, or pretty close to the minimum 9.75" recommended radius.

    How well a given pair of coupled cars/engines will negotiate a given transition also depends on the length from the coupling interface to the truck pivot, the distance between truck pivots (wheelbase), and how well each matches between the two cars/engines.
     
    EsK likes this.
  10. EsK

    EsK TrainBoard Member

    60
    19
    4
    Good to know the practical aspects & math behind this. It's a tight learning curve for me! Unfortunately it's too late for me to implement it in this layout so have saved this post with the formulas for future reference.

    Fully agree with your observation that it also depends on a host of other coupling factors because I am facing no issues with these locomotives with some other (even longer) Kato passenger cars.

    Thanks,
    Krish
     
  11. BNSF FAN

    BNSF FAN TrainBoard Supporter

    6,825
    10,812
    118
    I would agree on the body mount normally for that situation but the car in the pic is a coal hopper with trucks right at the end edge of the car so I think the lateral pull on a body mount on that type of car would still be an issue, maybe?
     
    EsK likes this.
  12. EsK

    EsK TrainBoard Member

    60
    19
    4
    This missile car (pic attached) holds up just well, doesn’t jump rails on any of the sharp curves. It’s a truck mount. Am also attaching a pic of the Kato coal hopper with trucks right at the end edge of the car. Does this give an idea whether Micro-Trains N 00302044 (1038) Barber Roller Bearing Trucks with Long Extension Couplers could be a suitable option?
    Thanks,
    Krish

    This coupling works 1.jpg This coupling works 2.jpg
     

    Attached Files:

  13. NtheBasement

    NtheBasement TrainBoard Member

    246
    189
    14
    Long shank should do the trick. Thats a modern twin tub, everything for the past 50 (60?) years is Roller Bearing, so you want a long shank roller bearing truck. Medium shank might look better but might not solve the problem.

    The issue is you have body mount on the loco and truck mount on the cars. Body mounts swing wide to the outside of curves. Truck mounts stay closer to the center of the track, and the short shanks can't reach far enough to the side to stay coupled without turning the truck off the rails.
     
    EsK and mtntrainman like this.
  14. EsK

    EsK TrainBoard Member

    60
    19
    4
    Yes, that's exactly what's happening. Though the Kato hoppers have truck mount, the couplers are short shank and themselves don't swing a lot and so it almost behaves like a body mount, forcing the coupler out of range just at the most critical point on the curve.

    Guess will try out Micro-Trains N 00302044 (1038) Barber Roller Bearing Trucks with Long Extension Couplers as suggested by BSNF Fan first & if that doesn't work then will try the body mount as suggested by NS737.
    Will report back once I have tried the M/T 1038.

    Thanks guys!
    Krish
     
    BNSF FAN and Hardcoaler like this.
  15. bill pearce

    bill pearce TrainBoard Member

    588
    234
    18
    I've tried to hold this out for another time, but here it is. What we have here is problem that is timeless. What this problem cries out for is Z scale. But too few stores, online and brick and mortar don't carry enough to see what's out there, so the market is tight for new locos and cars. And don't forget our greatest enemy, younger people are totally uninterested in working with their hands, they prefer the Chinese to do that for them, so any form of scratchbuilding is out.

    I'm hiding behind sandbags, let the shooting begin.

    Oh well...
     
    BNSF FAN and digimar52 like this.
  16. BigJake

    BigJake TrainBoard Member

    305
    226
    10
    Well, Bill, you did post that in the N Scale forum...

    But you make an excellent point regarding picking a scale that meets your needs.

    However, those needs can be a lot more than just available space for a layout. Available product variety is another important need, where N scale is much better than Z, but worse than HO.

    And then there's sound decoders...
     
    BNSF FAN likes this.
  17. BigJake

    BigJake TrainBoard Member

    305
    226
    10
    I would also say that the smaller the radius of curvature, the more important it is to view the layout at close to eye level, where the disjointed appearance of trains on short radius curves is less apparent.
     
    BNSF FAN and Hardcoaler like this.
  18. bill pearce

    bill pearce TrainBoard Member

    588
    234
    18
    It has occurred to me that I missed something. When I built my layout I used flex track, so it was easy to include easements into curves..Would I be correct in saying that by using the toy train plastic roadbed track this would be impossible? Could this be the source of your problems?
     
  19. mtntrainman

    mtntrainman TrainBoard Supporter

    7,947
    2,934
    119
    One of the great things about Kato Unitrak is that the pieces are mathematically exact and completely interchangeable. Everything is based on degrees of arc. You do not need to make a complete curve entirely from the same radius pieces. For instance, you can start at the straight tangent using a 28.25" curve for 15 degrees, then attach a 19" radius piece for 30 degrees, then a 15" radius for 30 degrees, then a 13.75" radius piece, and so forth. The result is a perfectly smooth curve of increasingly tighter radius. Using the larger radius pieces at the starting and ending tangents make perfect (kinda perfect) transition easements. The other great thing about Kato is that if you have trouble with the math you can lay out the pieces and snap together to see what's what.

    http://cs.trains.com/mrr/f/11/t/255017.aspx
     
    MK, NorsemanJack and BNSF FAN like this.
  20. BigJake

    BigJake TrainBoard Member

    305
    226
    10
    As pointed out by mtntrainman, you would be incorrect; easements are both possible and practical when using Kato Unitrack or similar products from Tomix.

    However, it is discourteous to refer to Kato Unitrack as "the toy train plastic roadbed track," unless you also refer to all model trains, trackage, structures and scenery as "toys" too. Referring to some styles and products as toys, while others are "serious models", discounts the joy, accomplishments, and the commercial market represented (and required) by both groups.

    Many modelers use Unitrack to make beautiful, elaborate, functional and reliable layouts, many of which can be seen here on Trainboard.

    We all are able to model at our own level of skill and fidelity, and perhaps even to aspire to greater levels of each. But when we dismiss modelers with less time or talent (lets not stop there; what about knowledge and experience), we dismiss our own hobby that is what it is because we co-exist.

    With whom would we usefully share our hard won lessons, without those who have not learned them yet?

    I love a good layout with hand laid track and switches! I especially admire the time and effort dedicated to the creation of layouts like that. But not all of us have the time or skill to do that, and yet some still manage to create fantastic layouts that are attractive, functional and reliable using sectional track with "plastic roadbed". Are "true modelers" not allowed to use anything but cork for roadbed?

    And how many hand tie & rail layers started out with sectional track when they first encountered the hobby? Where would they be if not introduced to the hobby through such "toys"?

    Along these lines, I have seen attendees "thumb their nose" at the increasingly popular Lego railroad displays at train shows. Can't we all see how the excitement these layouts foster, evident in the eyes of young and old, nourishes the seeds that will grow into enthusiastic practitioners, providing the future life-blood of our hobby?!

    One of the most amazing attributes of Kato (and Tomix) track is that, while maintaining excellent reliability, elaborate and effective layouts can be built on the floor by young modelers in the morning, run all afternoon, then dismantled and put away by bedtime! And each morning provides a new adventure, with yet another empire to be built, run and dismantled, over and over again. Who are any of us to dismiss these means as mere toys that have no place in our esteemed hobby?!

    Harrumph!
     
    Onizukachan, EsK, MK and 2 others like this.

Share This Page