Microtrains-kato Turn derailments

salamander34 Feb 11, 2020

  1. salamander34

    salamander34 New Member

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    Hello all! this is my first post on here so hopefully someone can help me out here. Ive been working on a 2x4 n scale layout that ive made DCC. I purchased a BLI diesel locomotive and Kato freight cars. The BLI loco has microtrains couplers and the Kato cars have Kato couplers. whenever the loco goes to make the turn it derails the front trucks of the kato freight cars. the turns are kato r216-45s. Now the KATO locomotive(same bodystyle same unit) has no issues towing the cars around this curve at all. It seems to me that the coupler on the BLI loco is dragging the front trucks off of the track and im not sure why. is it because the microtrains coupler has a shorter shank? I would like to install the Kato coupler onto the BLI loco but the way Kato couplers are set up im not sure if thats possible. Has anyone tried to install KATO couplers on a regular coupler spot? any advice would be greatly appreciated.
     
  2. MP333

    MP333 TrainBoard Supporter

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    Welcome to TrainBoard! For starters, I'll ask a few questions to help narrow this down. Someone else hopefully with more direct info will pop in.

    What is the radius of the curve you are on? What kind of cars are they? Do you know if the cars are properly weighted?

    I would resist using the Kato couplers on a loco. I've not had good luck with them, and much prefer MTs or Accumates. But you will get a lot of opinions on that one. My Kato equipped cars work fine, but are hard to get coupled compared to the other brands.
     
    BarstowRick likes this.
  3. Hardcoaler

    Hardcoaler TrainBoard Member

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    Those are very tight curves, about 8-9/16" radius. I think this is contributing to your derailments. If you're operating a six-axle locomotive, the effect will be even more pronounced. Even BLI's little four axle NW-2 has a recommended minimum radius of 9-3/4". Too, the points on Kato's No. 4 turnouts sometimes don't close tightly on the stock (main) rail, so you might look for gaps there. But, I think your tight curvature is your primary problem.
     
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  4. Inkaneer

    Inkaneer TrainBoard Member

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    The problem is twofold. First, you have very tight curves. On a layout only two feet wide you probably have curves of 9 3/4 inches or less. I think the Kato 216-45 curves scale out to 8.5 inches which is below minimum radius (9 3/4 inches) for N scale. The second problem is your locomotive, you don't state what it is but it probably has a body mounted coupler. A long wheel base locomotive with body mounted couplers going around a super tight curve will pull the first car off the track every time. The easiest and cheapest solution is to widen the curves to about 16 inches or more. That will require you to increase the size of the layout to 3 X 4 feet. You will need wider radius track also. Kato lists a R430-22.5 ( the radius is 430 mm or 16.9 inches and the arc is 22.5 degrees) You will need 16 of these to make a full circle (22.5 X 16=360). An alternate solution is to get a locomotive with a smaller wheelbase. However, you will still have the problem that your 8.3 in curves are below the recommended minimums for N scale. When it comes to curves, bigger is always better. Note that I do not have any BLI diesels and you do not state which model diesel you have. Post another message on this thread advising us of the model engine. Someone here will probably have that same engine and can tell you specifically how wide of a curve it requires.
     
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  5. MK

    MK TrainBoard Member

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    [Oops! Looks like we all chimed in at the same time but I'll keep my post anyway. :) ]

    The Kato curve you are using is too tight. It's 8-1/2" radius. They are good for very short locos like 44 Ton switchers, trams, etc. I don't know what BLI locomotive you have but regardless it's probably too long. As you surmise the rear coupler of the BLI is most likely pulling off the front truck of the rolling stock immediately behind the loco. Change to 9-3/4" minimum, less curve even better if you have the space and your problem will go away. No need to change any of your rolling equipment.

    So why does your Kato loco work? Well, 99% of Kato locos are designed to work with 9-3/4" radius curves so you are kind of lucky that it works with 8-1/2".

    Since you are using a 2x4 base, you can use 9-3/4" and 11" radii to make a double oval (been there, done that :) ). If you are only doing one oval, I would stick with the 11". With 9-3/4", 95% of the stuff out there will run on it.
     
  6. NtheBasement

    NtheBasement TrainBoard Member

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    Thought I remembered a thread about an MTL coupler mod that allows the box (not just the shank) to swing left and right, but can't find it.

    Anyway, another approach might work: put car behind the loco with a long shank coupler on the loco end. These seem to have a bit more swing than the short shanks so they'll swing farther before the car gets pulled off to the outside of the curve, but visually there will be a big gap between the loco and the car.
     
    Hardcoaler likes this.
  7. salamander34

    salamander34 New Member

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    Thanks guys, i can see that the curve may be a little tight but on a 2x4 board with the layout I’m using it needs that tight curve. I’m using a BLI GEES44AC and the KATO loco is exactly the same but with KATO couplers and i have 0 issues with that one. Unfortunately the track is laid out, glued in place, and holes have been drilled for all the switches and power, so redoing the curves is out of the question. I would ultimately like to modify the BLI loco by taking that coupler off and swapping it with the KATO one I’m just not sure how to do that. Considering the KATO coupler is like a rectangle with the coupler coming out, and the micro trains one is the standard box. Would need some heavy modification.
     
  8. John Moore

    John Moore TrainBoard Supporter

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    I suspect you are operating on Kato 20-170 track which has a radius of 8 and 9/16 inches because I could not find a 216 in curved track. That is my mainline curves and there are tighter curves of 6 and 7 inches. Because of the tight curvature I only run locos that have a wheelbase of 2.25 inches and my cars are all of the 40 foot length. I run some cars with Kato couplers and others with MTs and the same goes for the locos and have no issues. I suspect that your issue may be the loco. But then it could also be body mount couplers on the cars not allowing enough swing action. However based on the loco it is probably the culprit with the body length and body mount couplers that are swinging to wide and retroing it with Kato couplers will not correct the issue.
     
    MK likes this.
  9. Rich_S

    Rich_S TrainBoard Member

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    You have a couple of options since your modeling space is limited.

    1) You could purchase a freight car with truck mounted Micro-Trains or Micro-Trains compatable couplers and always run this car between the BLI locomotive and the Kato freight cars

    or

    2) You could try replacing the Micro-Trains couplers on the BLI locomotive with their Medium Shank coupler and see if that helps.

    https://www.micro-trains.com/universal-bmc-medium-shank-assembled-1016-1-00102006?search=medium shank
     
  10. salamander34

    salamander34 New Member

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    Ive decided to tear up everything i have down and make a new setup as it wouldnt be that much of a hassle. in fact, its going to be double the size now anyway haha. seems like the curvature would have a negative impact on any BLI locos that i purchase in the future as i like long wheelbase locos. guess ill just have the build it bigger!
     
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  11. NtheBasement

    NtheBasement TrainBoard Member

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    There are all kinds of reasons to start over, but it might be worth your while to first buy a pair of MTL long shank trucks, put em on a car, hook it up to the loco, and see if it derails. If that fixes it you could see if medium shank trucks work too.
     
  12. Point353

    Point353 TrainBoard Member

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    When you plan your revised layout, consider adding a larger radius curve section as the first piece of track leading to or from straight track into curve.
    This will create a smoother transition between straights and curves, as is done on the prototype.

    Assuming that you'll still be using Unitrack, try to begin and end each curve with one section of Kato 19" track #20-160.
    For even smoother operation use one section of 28-1/4" track #20-150, followed by one section of Kato 19" track #20-160 and then whatever tighter radius curve track you plan to use.
     
  13. ns737

    ns737 TrainBoard Supporter

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    the swing of the engine on the curve is pulling the truck mounted coupler off the track. how i fixed this problem is I made lead cars with one end body mounted coupler. this way the car body swings out with the engine and the car truck navigates the curve. It has worked for me.
     
    mtntrainman likes this.
  14. salamander34

    salamander34 New Member

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    For now I’m going to use KATO locomotives only for the time being as my radius cannot change. I’ve expanded to a 2x5 and a 2x5 9” in an L shape. Hopefully i can get some DCC sound installed on these katos
     
  15. MK

    MK TrainBoard Member

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    Just a heads up that a sound install in Kato locos will require frame cutting.
     
  16. salamander34

    salamander34 New Member

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    I know, I’m willing to put in a little work to get my desired outcome, I’ll just have to look up some videos I’ve got the hobby experience to figure it out haha
     
  17. MK

    MK TrainBoard Member

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    salamander34 likes this.
  18. salamander34

    salamander34 New Member

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