Help! MTL Turnout Issue

jshglass Mar 8, 2018

  1. jshglass

    jshglass TrainBoard Member

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    Just on the switch. It goes through the straight just fine. Here’s a picture of it and how things are wired.[​IMG]


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  2. Thieu

    Thieu TrainBoard Member

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    These switches are not power routing, so I do not understand the shorts you have.
     
  3. acptulsa

    acptulsa TrainBoard Member

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    Usually that sort of behavior is caused by wide locomotive wheels touching both the straight rail and the curved rail at the frog.
     
  4. jshglass

    jshglass TrainBoard Member

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    Is there a fix for that?


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  5. acptulsa

    acptulsa TrainBoard Member

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    Well, the first step is making sure that's the problem--which I've never done in Z. It may require a microscope.

    If you're not running DCC, I'd make extra sure of my wiring by putting the train on the other track and making sure it goes the same direction. If it moves left to right on one track, it should move left to right on the other. If it doesn't, you don't have it wired the way you say you do, and that's the trouble.

    If the locomotive's short enough, you can put it on the crossover between frogs to see if it's only a problem when the wheel is right on the frog. Otherwise, put the front truck on the crossover and the other truck back at the points, so one truck is on the crossover and no wheels are on the frog. Then see if it moves an inch before the rear wheels reach the frog.

    If so, sometimes getting the gauge of the wheels just right (making sure the wheels are just the right distance apart on the axle) can eliminate the problem. Otherwise, you need either narrower wheels or a wider gap between those metal rails. Either could be something of a pain in the neck (or lower down). A tiny spot of non-conducting paint right at the spot where the straight and curved rails meet can alleviate it--until the paint gets worn off. Make sure it's nonconductive paint, or you'll have a short until you scrape every bit of it back off!
     
    Last edited: Oct 7, 2018
  6. Garth-H

    Garth-H TrainBoard Supporter

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    The MTL turnouts are power everywhere, and are designed with internal switch to power frog and do not depend on point rail however it is possible with repeated handling to loose contract to some pieces especially piece beyond the frog, it is possible to make solder joints under the roadbed to correct this but you need a very fine point with a 15 watt iron. use a electronic solder with flux core and very small OD used for soldering surface mount devices. It is possible if the turnouts have been sitting in the open that thee is oxidation on the brass contact on circuit board switch under the roadbed of the turnout as that makes all the connection to various pieces including the frog. it is easy to access and clean with rubbing alcohol and track cleaning block. take pictures as you open bottom of turnout so you can put it back together properly. In the days before Rokuhan I used to modify these turnout for power routing and putting LEDs in roadbed to show track polarity when crossing blocks, so I am quite familiar with the insides of these turnouts
     
  7. Garth-H

    Garth-H TrainBoard Supporter

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  8. acptulsa

    acptulsa TrainBoard Member

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    That might explain it. When the loose contact does lose contact, can the weight of the locomotive tighten it up and cause it to regain contact?

    If so, the locomotive passing over one switch when insulated joiners are used can't restore power to both rails. But when metal joiners are used, the weight of the locomotive can restore contact in one switch long enough to cause a short.

    What if he doesn't want "power everywhere"? Is there an easy way to disconnect those rails for good at the frog, so he can use metal joiners?
     
  9. SJ Z-man

    SJ Z-man TrainBoard Member

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    This is easy.
    #1 You weathered the rails. This 'wicks' into the contacts of the internals. The tracks have a small ball that contacts the rails and we've seen a dozen that had issues from this, when the paint dried.
    #2. Using the image, you can see that each frog exit rail (the short one the divergent routes) are connected the Stock rails (the long continuous outer rails). Using the upper left turnout, bottom rail, left to right, drops into the frog of the lower turnout frog. As long as that lower turnout is switched (as shown), the frog polarity will match and there will not be a short.
    Using the opposite, starting on the bottom right to left, that exit rail (tip of blue arrow) will run into a frog with incorrect polarity.

    Track wiring is fine, the added joiners to the exit rails helps extend the power up to the frog.
    That leaves the frog. Get a old-school volt meter with s pointer or, 12 volt flashlight bulb (solder to wires to the bulb) or spare motor and use to probe each rail and frog.
    Start at the upper left, top rail to the lower rail (same track) and points and frog and divergent rail to lower frog. The meter/bulb/motor should indicate you have a good connection. Switch the turnouts to validate the points and frog power is correct in both positions.
     
  10. jshglass

    jshglass TrainBoard Member

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    I’m putting an end to this thread. I just took the turnouts apart and cleaned every surface I could find. Tested again with a continuity meter and the frogs are just dead.

    D-E-D: Dead

    I’m ordering two Rokuhan turnouts to start. If they work they way they’re supposed to, I’m replacing every turnout on the layout.

    Thanks for everyone’s help and patience!



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  11. SJ Z-man

    SJ Z-man TrainBoard Member

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    Hmmmm, if they are dead, they could be missing the finger/leaf contacts, like a bunch of turnouts we got after they resurrected the track.
    Might check with the 'boss', Sara about spares.

    At least you have a solution.
    My first non-handlaid turnout will be the Atlas ones.
     
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