Help! MTL Turnout Issue

jshglass Mar 8, 2018

  1. jshglass

    jshglass TrainBoard Member

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    Hi Again,

    Sorry to flood the forum with so many posts, but things are starting to ramp up in my layout construction. Seeing as I'm new to this I'm now running into issues more frequently.

    I am laying track now. My little GP38-2 is running nicely on my periodic test runs, but it's encountering trouble on a turnout. It'll pass through smoothly on the straight, but get locked up when the switch is thrown. I can hear the motor firing when it gets stuck, so that tells me it's still getting electricity. (Right?)

    Is this making sense, or should I post a video?

    Thanks,
    Josh in Philadelphia
     
  2. shamoo737

    shamoo737 Staff Member TrainBoard Supporter

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    You may want to widen the gap near the frog. See if the wheels are getting stuck in that area. Early MTL switches are build to a too tight tolerance.
     
  3. markm

    markm TrainBoard Supporter

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  4. markm

    markm TrainBoard Supporter

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  5. jshglass

    jshglass TrainBoard Member

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    Hmm. From what I'm gathering, I should rip out all of my turnouts and replace them with Rokuhan. That is unless I want to tinker without any guarantee of success.

    Are the Rokuhan dimensions the same? For that matter, what about the new Atlas turnouts everyone is starting to go crazy over? How are those powered?
     
  6. markm

    markm TrainBoard Supporter

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    Josh,

    The MTL turnout isn't a bad turnout, I'd say that 80-90% of the ones I've purchased have worked well for me. As you have noted from the other thread, most of the problem can be corrected with a bit of find grit sandpaper and a vacuum. The units I've had problems with came from the resale circuit, for what it's worth.If you test out all the turnouts well before mounting them, I suspect you'll have few problems.

    Yes you could replace the MTL with the Rokuhan, they use the same footprint. There are small differences with rail and roadbed height that needs to be consider but can be easily handled.

    The Atlas turnouts are another story. The modeler is left with the problem of routing the power and controlling the throw. The physical layout is also different from all the existing Z scale turnouts, matching a designed used in larger scales and the prototypes. To sum it up quickly, the Z world has been 13° turnouts and Atlas is giving us 19° units. So existing sectional track doesn't exist and you are looking at using flex track or hand cutting sectional.

    Mark
     
    Last edited: Mar 8, 2018
    z.scale.hobo likes this.
  7. SJ Z-man

    SJ Z-man TrainBoard Member

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    No, you don't have to rip them out. You likely just need a small jewelers file, something you should already have. @$5 for the cheapest set to $20 for good quality. Just make sure they are thin. Some are noticeably thicker.

    On the 'outer' rails (call Stock Rail), there is a black Guard rail. This is usually the sticking point (to simplify all the forum talk). Place the jewelers file between the metal and plastic 'rail' to open the gap a bit.

    It's not MTL's fault as their products work fine. It is. as said before, that the tolerances in the scale can be variable. There is no hard and fast explicit standard.

    To know where the problem is, get a good desk lamp and flashlight. I like the headlamps. Manually slide the loco thru the turnout. You should be able to determine which truck and which axle is creating the binding. Sometimes you need to put a mirror on the rails in front or back of the loco to see 'under' it.

    If the loco stalls on the turnout, get your $5 Harbor Freight voltmeter and probe all the rail surfaces. Place one probe outside the turnout (not on the turnout itself) and then probe the frog area or points. The points 'float; so may not make contact once the front wheels touch them or, when on the frog. Some locos have poor pickup on one truck and it may not be all that noticeable on the straight/curves (non-turnout) track.
     
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  8. jshglass

    jshglass TrainBoard Member

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    I don't own a thin enough file. I'll get on that. Thanks. In the meantime, what do I do if there isn't any power in the turnout? How do I go about fixing that problem?

    I have been testing this all day (it feels like), and am getting pretty frustrated. Going to take a break for a day or two and come back to it later (once I have the file). What is frustrating is not that the engine gets stuck or stalls out. What's frustrating is that the engine can make one successful pass (or two) and on the next go 'round it will get stuck or stall. No variables were changed at all.

    I've also noticed it'll stall out more going at lower speeds. Top speed it'll either get stuck or go through just fine.
     
  9. jshglass

    jshglass TrainBoard Member

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    Hot diggity! I hard scrub with some fine sandpaper did the trick just fine!

    It’s still losing power at very low speeds, though. Is this just the nature of Z scale?


    Sent from my iPhone using Tapatalk
     
  10. z.scale.hobo

    z.scale.hobo TrainBoard Member

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    Not necessarily the nature of z but definitely one of the challenges.

    I made a video showing some slow-speed running of Marklin F7's with 3-pole motors. Many folks consider these inferior to many later locomotives. This video shows that slow speeds up and down gradients can be achieved if the conditions are controlled (clean tracks, clean trucks, clean gears).

     
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  11. jshglass

    jshglass TrainBoard Member

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    So are you suggesting I clean my track/trucks? My multimeter is telling me I'm getting more than sufficient power to the frog, so I don't think its s circuitry issue. Low voltage just seems to be the loco's kryptonite in the turnout.
     
  12. SJ Z-man

    SJ Z-man TrainBoard Member

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    Could be the truck pickup. Turn the loco around and where does it now stall? The Exit rails (the short ones on the frog) are power routing. The Frog power is switched, along with the points. but these are very light contact parts. If your meter indicates that the frog has power and the loco has at least one axle in the frog, then it is truck power pickup issue. This could be dirty wheels (generally clean from the factory) and only dirty from running with plastic wheel freight, dust, etc., the truck-to-frame pickup, etc. How sensitive is it to recovering from the stall? light tough here? There? You could take the shell off to test power pick. When it stalls, probe from one rail and to the chassis frame on the opposite side. You should be able to just lay the metal probe tip on the frame surface to know, not disturbing any frame or truck positions.

    Having another locomotive helps, especially if it is from another manufacturer.
     
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  13. ModelWarships

    ModelWarships TrainBoard Member

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    If you don't have a file, you can use an exacto knife to scrape away at the plastic guard rail. Drag the blade sideways to open up the tolerance a bit. It helped on my original layout, but I finally bit the bullet and replaced them with Rokuhan ones.
     
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  14. jshglass

    jshglass TrainBoard Member

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    Hi Everyone,

    It's been a long while since I've posted anything, but my life has finally slowed down a bit to the point where I had an hour or so to kill pulling my hair out over these damn turnouts. (I just wanna start the scenery!) After much testing, here is what I am noticing. Hoping maybe this time I'll be able to resolve this issue without having to take my layout to the hobby shop and beg the grumpy old man who owns it to help me out. :cry:

    I am getting nine volts across the blocks, no problem. So that proves to me there is nothing wrong with my wiring. (HURRAH!) I am running an AZL GP38-2 that seems to work just fine until...

    Down to the nitty-gritty: the turnouts. The points are working just fine, as I see the polarity flips depending on how they are thrown. No issue there.

    The frog, however, is dead on every turnout. Is this supposed to be the case? The little exit rail on the inside of the turnout (the one not connected to anything) also doesn't seem to be getting any power either. Is this supposed to be the case? I'm assuming this is where my problem lies, as this is where the loco either dies (when switch is thrown) or jerks (when going through the straight). Both of these things happen while traveling in both directions.

    Can I attach a jumper wire to that little rail? Would that help? Does the frog need to be powered?

    Additionally (and this is not the most pressing issue right now), sometimes my loco will either sputter on a normal piece of track or stop all together. Is this just due to dirt? Every time this happens I clean the track. It seems to get better, but the problem is still there every now and then. First thing's first, though: the turnouts.

    Sorry to anyone who is annoyed that I am still on this issue.

    -Josh in Philly
     
  15. z.scale.hobo

    z.scale.hobo TrainBoard Member

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    "my loco..." Which one matters. "normal piece of track" - curve or straightaway?

    If a GP38-2 from AZL, you might have to re-seat the circuit board as they can get intermittent. I also found that the metal strips from the chassis to the trucks can be not making good contact as well, leading to stalling. These strips might also have buildup at the interface to the strips from the trucks and might need to be cleaned.
     
  16. shamoo737

    shamoo737 Staff Member TrainBoard Supporter

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    Check the wheels of the Gp38. It has traction tires, and it’s more likely to stall on turnouts.
     
  17. jshglass

    jshglass TrainBoard Member

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    All “normal” track that isn’t a turnout, I mean.

    How do you suggest I clean the copper pickups on the trucks? Also, what would you suggest I use to clean the track? I’ve been doing one thing, but I don’t know if it’s the preferred method.


    Sent from my iPhone using Tapatalk
     
  18. jshglass

    jshglass TrainBoard Member

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    Are you suggesting I take the traction bands off the wheels? You think that would help? I’ve it’s gone through turnouts before. Just not between blocks.


    Sent from my iPhone using Tapatalk
     
  19. markm

    markm TrainBoard Supporter

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    Josh,

    For cleaning track I like to use electronics grade alcohol wipes for really dirty track. Not so dirty I have a locomotive push an Aztec track cleaning car.

    I would discourage you from removing the traction tires.

    I am a bit confused by your statement: "I am getting nine volts across the blocks, no problem."
    Does this mean that if you measure from rail "A" in block one and the same rail in block two you measure 9V?

    Mark
     
  20. ddechamp71

    ddechamp71 TrainBoard Member

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    A few comments come to my mind from what is written above...
    -MTL's turnout frog should be under power every time. These turnouts are not considered as "true" power routing by specialists (I don't even know why) but anyway they are designed to be continuously powered from points to diverging track. But myself I also had issues with them (using MTL Geeps, which are probably the best Z scale locos dealing with power pick-up), so I don't use them anymore. Sad, as they are very eye catching for an american prototype modeller, but I can't accept the least glitch in their way of working, as I am a shortline / switching / slow speed operator (so I wound up building mine using Fast-Tracks gigs, and I'm now waiting to the long waited Atlas samples to be released). But an option I had in mind a while ago would be removing all the underneath stuff, and powering frog and points soldering wires on, like on a "real" power-routing turnout.
    -About AZL locos' traction tires. A friend of mine, Jeff Merillot (maybe some of you here know him, he's a very tallented Z-scaler who builds everyone of his - huge - layouts the time I'm needing to kitbash a single locomotive, using handlaid tracks and turnouts), has deliberately removed his AZL locos' traction tires, and it's not an issue for him, especially on turnouts, even with the resulting couple of grooved wheels on everyone of his locos.

    Dom
     

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