working helix?

Discussion in 'N / Z Scale Model Trains' started by Muddy, Mar 14, 2007.

  1. Muddy

    Muddy New Member

    Hi all have built a 3'x6' oval to run but I think that with the space I have it could be better used with a 1' wide shelf layout that could extend 8' along one wall and 12' around the corner instead of a circle on a table that knocks out 25% of my family room. I then thought that this shelf could be 2 or even 3 spaced out 12 to 14 inches vertically {got this from MR article} and have a functioning railway with several stops, {ambitious ain't he} but looking into a helix is a dissuading subject.

    Would like to know your experiences both positive and negative to plan mine ie rad, grad, laps and spacing [ have visited the calculator but you can input any numbers you want to make it work, but is it practicable}

    You feedback will be appreciated.

    regards: Johnny
  2. 60103

    60103 Pooh Bah

    The factors for your helix are vertical spacing between laps, radius and grade. Laps will depend on the vertical spacing between main layout sections.
    Assume you want a 3" climb per lap and a 2% grade maximum. Each lap will be 3"/2% (3/.02) or 150" long. Divide by pi (22/7) and this is nearly 48" diameter.
    You can cut this down with a steeper grade and/or less climb per lap. 3" gives you a bit of room to put a finger or two around the train and 3/" or so for track, roadbed and sub-roadbed.
  3. baldwinjl

    baldwinjl Member

    The other thing you can do is make a oblong helix if can't afford all the space of a circle. then you could use a smaller radius to get the same elevation. It's just a trade of one dimension for another.
  4. rsn48

    rsn48 Member

    Have you looked in Armstrong's book - Track Planning for Realistic Operations? What radius you are looking at is contingent on inches of seperation between levels; 2 1/2 inches of seperation will be a 2.1 grade with an 18 inch radius; 20 inch radius with the same seperation will give you a 1.9 grade.

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