Micro Train Uncoupler Problems

Discussion in 'N / Z Scale Model Trains' started by jland31, Feb 25, 2003.

  1. jland31

    jland31 Member

    Need some help!

    My layout has 14 turnouts with lotsa switching & coupling/uncoupling opportunities.
    I've installed 7 undertrack magnets which generally work well.

    Occasionally I'll buy a new M/T car that won't uncouple although the coupler swings when run over the magnet. It just won't let go of the mating coupler.

    I do all the checks & adjustments that M/T recommends & spray with Grease Em. Doesn't help.

    What say you experts? What am I missing here? Need to magnetically uncouple as the layout is 4'6" x 8' & some locations are hard to reach.
  2. Vic

    Vic Active Member

    Although I don't model N scale I do use MT couplers on HOn3 cars. There's a few things that could cause the problem.

    1. The coupler is binding or is not returning to center. Make sure that it will swing freely in both directions and return to center.

    2. The centering spring inside the box is out of place.

    3. Look for "burrs" on the coupler shank and on the edges of the coupler boxes. When using the Grease Em make sure to get some inside of the coupler box.

    4. The "lid" of the coupler box is fastened down too tight.

    5. The track magnet is not located on the center line of the track

    6. The magnet is located too close to a curve in the track and while the car to be uncoupled is straight the car that it is coupled to is still on the curve and is causing the couplers to be off center to each other.

    Hope this helps:)
  3. Tyson Rayles

    Tyson Rayles Active Member

    What Vic said! :)
  4. nmtexman

    nmtexman Member

    Another problem can be caused by the "yo-yo" effect sometimes produced by MT couplers. This is caused by the springs in the coupler and looks like a accordion in action. If this is happening when you are passing over a in-track magnet, then the couplers may not be applying pressure to each other at that moment, and the cars will uncouple.

    I've had this happen to me at a GATS show recently. There was an improperly placed connector track between two modules. The second module had an in-track magnet uncoupling station on it. As my cars passed over the bad connector, the would start the "yo-yo" action and cars would uncouple at random.
  5. jland31

    jland31 Member

    Micro Train Uncoupler

    Hey you guys;

    Thanx for your input. Seems that a great deal of my problems are because of small burrs in the coupler. These burrs keep the couplers from disengaging.

    Whats the best method to use to remove these small imperfections?
  6. nmtexman

    nmtexman Member

    Try a small file.
  7. Vic

    Vic Active Member

    I like to use an Xacto knife with a new sharp blade in it. Don't try to "slice" the burrr off just sorta scrape at it gently with the edge of the blade.
  8. 60103

    60103 Pooh Bah

    You don't say where your burr is, but any filing or scraping should be in the direction of movement of the parts. On the front knuckle, file across. On the moving parts inside the coupler box, it's probably also across. You don't want to make scratches that will catch on each other when it moves.

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