Model Railway Speed Gauge

Discussion in 'Tips & Tricks' started by kiwi1942, Aug 4, 2008.

  1. kiwi1942

    kiwi1942 New Member

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    HI
    I am wondering if the is a FORMULA to calculate the speed of a model Railway
  2. Nomad

    Nomad Active Member

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  3. kiwi1942

    kiwi1942 New Member

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    Gauge Speed

    Thanks for this

    looks like I have to go back to school
  4. cidchase

    cidchase Active Member

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    If it's HO:

    measure the distance in inches that your train travels in 5 seconds.
    This is the same as the scale speed in MPH (about 1% error).

    If it's N, THEN you have to go back to school:mrgreen::mrgreen:
  5. kiwi1942

    kiwi1942 New Member

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    HO Speed

    Yes indeed its HO

    thought we were smart while at a EXPO when someone asked us what was the REAL SPEED, we omitted we had no idea of hand, so hence here or somewhere looking around, then we decided to do a test ourselves as follows

    10 fingars span = 9 inches x 10 = 90 inches,
    taking 12.14 seconds, not sure where to go from here

    inches into miles x seconds into hrs, now looking for the calculator

    90 / 63360(inches in mile) = 0.00142045e x 60 x 60 = 3600(seconds per hr), :) on my calculator this reads 5.11362, ??? mph or s there mre to add, like 1.87 scale

    I AM NOW REALLY CONFUSED

    THANKS 4 ur reply
  6. nolatron

    nolatron Member

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  7. kiwi1942

    kiwi1942 New Member

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    So I am nearly right with my sums then or so far away it dont matter, sorry to say can not afford one of them for now
  8. cidchase

    cidchase Active Member

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    9" in 12.14 s =
    3.71 " in 5 s (9*5/12.14)
    or
    3.71 scalemph (estimated by the 5 second rule)
    or
    3.67 scalemph (true value)

    How close did you measure the 12.14 seconds?:mrgreen::mrgreen: BTW, I don't see the 12.14 seconds in your calculation. And yes, you can multiply the true speed by 87.1 to get the scale speed. The distance is scaled, but the time is always constant.
  9. cidchase

    cidchase Active Member

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    Again, with your second hand or stop watch, measure the distance (in inches) traveled in 5 seconds (easy way).

    If you travel 36" in 5 sec, you are going 36 scale mph (small error).

    The true value is 36 X 87.1 / 88 or 35.63. This error (1.02%) might be less than you can really measure with your second hand!! :mrgreen::mrgreen: