I hate those stalling switchers!

Schraddel Jul 1, 2010

  1. Schraddel

    Schraddel TrainBoard Member

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    Hello Folks!

    Imagine you are building a new layout with a lot of switches und schwitching activity.
    O.k. you have foreseen difficulties with picking up electrical current and so all frogs are live frogs und all points got soldered wire connections.

    So take a steamer which got modifications for all wheel pick up, all six loco wheels und all 8 tender wheels, in my case a typical 0-6-0, let it crawl like a snail across the layout and it will do the job to your satisfaction. No stalling, no flickering lights just steady crawling.

    And now the diesel. It's a new one, an Athearn MP15AC of the Genesis line. One of the newest model constructions too. Latest drive train technology, smooth motor, all wheel pick up and additionally equipped with an ESU V3.0 DCC decoder. The Back EMF enables it to crawl slower as any snail.
    Put it on the track and start running.
    So here it comes...
    But what is that???
    It stalls , lights off und dead?
    O.K. may be some dust on the tracks, so clean it again.
    Second try. Again it stall on the same spot.
    ähh...
    Are the wheels clean?
    Yes they are, but clean it again.
    Third try, same spot, dead stall.
    Nnnnng:teeth2:

    Why?
    I decided here at this stage to do private investigations.
    And this what i found:
    [​IMG]


    Both trucks are the same castings. Here ist the front truck. The main frame will beared by these two half round extensions. On the rear truck ist is just the same.
    For that reason ist is a 4-point suspension. An a table with four legs will rock everytime while a table with three legs never rocks.
    So it is possible that 3 of the 4 wheels on one side of the loco can have "airtime" whle the forth wheel, which ist now the only wheel which can deliver electrcity, ist just standing on an piece of mosquitoschiß! (Sorry Kraftausdruck)

    What to do?
    Yes the solution ist simple. Remove on one truck these half rounds anf replace them with something to let the Mainframe bear on the center of the truck.


    [​IMG]

    Measure the height of the half rounds, it is app. 1.5mm and then.

    Cut!


    [​IMG]

    I found an piece of suitable aluminium tube. Washers will do the job also.

    Reassemble the loco.
    Put it on the tracks.
    Run it.
    Crawl it.
    Crawl it over the switches.
    Crawl it over unveven tracks.
    No stalling! Just steady crawling.

    My question:
    Could this done at the factory?

    Greetings Lutz
     
    Last edited by a moderator: Jul 1, 2010
  2. COverton

    COverton TrainBoard Member

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    Das ist gut, Lutz!

    It would be worth sharing it in other places, as you have done here. Is there a yahoo group, for example. Maybe Athearn would be receptive to your suggestion. But I am impressed with your industry and perseverance. Well done.
     
  3. Jerry Tarvid

    Jerry Tarvid TrainBoard Member

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    Genius!:thumbs_up::thumbs_up:

    *****You went from a pair of two point solid rocking trucks to a pair of two point 360 degree pivoting trucks.***** Correction - You went from a pair of two point solid rocking trucks to a front truck with a center point 360 degree pivoting truck and an unmodified rear truck.

    Nice fix! I would patent that before the big guys do. No joke.

    Jerry
     
    Last edited by a moderator: Jul 1, 2010
  4. Dee Das

    Dee Das TrainBoard Member

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    Sheer genius!
    Excellent post and great photos. Ok, now where's that sandpaper?

    and this line:
    Thank You for brightening up my day.
     
  5. Mike Sheridan

    Mike Sheridan TrainBoard Member

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    Very interesting. I wonder if that is the problem with my P2k SW9 which I rewheeled trying to overcome those symptoms - to no avail :(

    New job on 'to do' list :)
     
  6. Schraddel

    Schraddel TrainBoard Member

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    Hello Jerry!

    You have to do this only with one truck. I choose the front truck in this example.

    The rear truck is still unmodified.

    Otherwise if modified too, the loco becomes unstable.
    Think of the table with the 3 legs. You need the 2 "legs" on the rear truck for stabilisation, the 3rd leg ist now the modified front truck which can swiveling and pivoting 360°.
    Thus you have a kind of tripod

    Greetings Lutz
     
  7. Jerry Tarvid

    Jerry Tarvid TrainBoard Member

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    Gotcha.:thumbs_up:

    Jerry
     
  8. gdamen

    gdamen TrainBoard Member

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    Another cause for this stalling problem is a bad contact due to those pesky plastic tabs. I always remove those tabs and solder the wires. In almost every loc I found tabs which hold only one or two strands of wire, which is a sure source of trouble.

    Best regards,

    Gino Damen
     

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