Loco speed

Discussion in 'N / Z Scale Model Trains' started by bigcozzz, Nov 26, 2006.

  1. bigcozzz

    bigcozzz New Member

    A few years ago I started my first layout with atlas track and gave up
    in total frustration.I've now begun again with Kato track and am much
    happier.I'm at the very bottom of the learning curve but reading the
    posts in this and other forums has tought me a lot pretty quickly.Lot
    more to learn but I'm having a great time. A couple of Q's if I may:
    1. Why do some locos run slower than others?
    2. Why do some locos slow down when they cross the main
    line end of a turnout?
    3. The Kato powerpack only has one plugin to run the train;
    a.Do you use that 3 way extention cord to run
    additional feeder tracks?
    b. Where do you get the power to run lights,signals
    and other acceseries?
    As you can see, I don't know very much and any help you can give would
    be greatly appreciated.
  2. Collyn

    Collyn Member

    1 different motors, weight, quality and electrical pickups
    2 there is probably sort of a dead spot in the center of the turnout
    3 and I have never seen a kato power pack so I cant help there
  3. pgandw

    pgandw Active Member

    1. Different manufacturer's gear their locomotives very differently, and not all motors have the same 12 volt RPM, anyway. Smaller motors usually have a higher RPM at the same voltage, but less torque. Some manufacturers even gear their own locos differently, depending on the model. LifeLike is notorious for the latter.

    Prototype diesels were geared differently, too, depending on the intended service. A strictly passenger unit (think E unit) would have gearing allowing a top speed in the 90 MPH range. This gearing rendered it pretty much useless for drag freight, which requires low speed power. An F unit might be geared for a top speed of 60 MPH. I'm sure there are those who know a lot more about diesel gearing than I.

    On steam locootives, driver diameter tended to control top speed because it was difficult to balance smaller drivers at high speeds. If a steam loco was operated too fast, the resulting jolts every revolution destroyed the engine and the track. Typically, top operating speed was the driver diameter in inches. Fast, modern and large driver locos could go faster (up to just over 100 MPH for some 80" driver locos); switchers could not go nearly as fast as their 50" drivers would indicate.

    DCC allows one to reset the speed curves for a given engine by reprogramming the CVs. By adjusting the speed curves, you are really adjusting how much voltage the motor gets for a given throttle setting. This way, you can set up your engines to run together well in consists. With DC, the engines have to reasonable matched in speed to begin with.

    Hope this helps
  4. bigcozzz

    bigcozzz New Member

    Thanks guys.

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