Helix Radius

TonyHammes Dec 14, 2017

  1. TonyHammes

    TonyHammes TrainBoard Member

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    Finishing up layout design right now. Will incorporate 2 separate helixes. Right now I have them at 42" radius. Was originally planning 36" radius. Just wondering if there is any good feedback on what route to go.

    Thanks
     
  2. RBrodzinsky

    RBrodzinsky November 18, 2022 Staff Member TrainBoard Supporter In Memoriam

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    Well, the larger the radius, you will have less issues with longer cars, but for N scale, 36" radius is fantastic (a 6 ft diameter circle). 48" radius is an 8 ft diameter circle. You really have that much room for 2 of either? Do you mean 36" and 48" diameters?
     
  3. nscalestation

    nscalestation TrainBoard Supporter

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    Tony,

    A 36 or 42 inch radius would be quite generous for N scale but if you have the space that's great. The helix on my own layout is 21 inch overall radius for the bench work with the tracks being 19.5 and 18 inches.

    Here is a link to all the posts in my layout blog related my constructing my helix. http://palisadecanyonrr.blogspot.com/search/label/helix
     
  4. HemiAdda2d

    HemiAdda2d Staff Member TrainBoard Supporter

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    Assuming you mean diameter, those are generous curves. On my last layout with the spiral (bowl shaped, not stacked) helix started with 15.5" radii and continuously increased radius to just over 20" radii and gained about 8". Ppuinn here helped me design it. His method is so easy to understand and idiot proof, I was able to build it! The best part of the spiral helix was unimpeded vertical access.
     
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  5. TonyHammes

    TonyHammes TrainBoard Member

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    Yes I mean diameter. Math not my strong point. That is why the Army made me Artillery.
     
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  6. John W Zerbe

    John W Zerbe TrainBoard Member

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    :eek::eek::eek:
     
  7. Hansel

    Hansel TrainBoard Member

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    I would have thought you would need more math for Artillery? LOL!

    If you can make the diameter larger the better. From my experience, a 30" diameter helix, I found that sharper curve limits the number of cars your loco can pull.
     
  8. bill pearce

    bill pearce TrainBoard Member

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    When I had a layout, it had a large radius helix. If you keep back issues of MRP, it's in the 1999 issue. I could stand up in it, which was too often necessary. I can offer suggestions based on my own not entirely pleasant experiences.
    1. Never again will I do a two level layout. I'll just model less. Too hard to deal with. hidden running is a pain.
    2. Doubt when I build another layout I will not use wood, but metal studs and cement board. Don't kid yourself, track doesn't expand and contract with temperature to any noticable degree, but wood expands and contracts form humidity or lack thereof to a startling degree. Hundreds of times more than track.
    3. Will never again cheap out and use Atlas code 70 track in hidden running. That stuff is crap. In the future it's ME code 40 all the way for me.
    4. No helix, it takes hours to get from one end to the next. If you must have one, provide a window or CCTV to monitor what's going on inside.
    5. Carpet the floor underneath it. Prototypical train lengths can string line in a heartbeat.

    Bill Pearce
     
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  9. hoyden

    hoyden TrainBoard Supporter

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    I did my 4.5x8.5 portable layout with metal studs to make it lighter and don't regret it. I used Homasote and that has so far been an okay choice with some sags but no show stoppers.

    I also used Peco c55 track because it is durable and comes in many different switch configurations; curved, slip, scissor crossover, three way. I used them all.

    I started the layout in 2011 and it has held up pretty well.
     
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  10. acptulsa

    acptulsa TrainBoard Member

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    Nobody's spelling it out for beginners, so I will try:

    1. A sharper curve means a smaller circle with a smaller circumference. Since each loop of the helix must rise enough to clear the loop beneath it, less circumference means a steeper grade.

    2. Taking a long train around in circles, especially uphill, means risking pulling the train off the track and into the middle of the circle. The sharper the curve, the greater the risk. Some people actually try to combat this with backwards superelevation--they bank the track so the train tilts toward the outside of the curve.

    I've never understood the appeal of "multi-floor" layouts either. Real trains don't run in wall diorama boxes. They run across the face of the Earth, usually with nothing over them but the sky.
     
    Last edited: Dec 18, 2017
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  11. SirTainly

    SirTainly TrainBoard Member

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    Essentially because it gives more real estate for your layout in a fixed sized room, which is great if you want more trackage for operations. Flat open layouts are great if you have the space, and want to model lots of non rail buildings or open scenery, but put too much track on a flat layout in a smaller space and you're in danger of heading into spaghetti bowl territory. I'm building multi deck as I've a room just under 8x16' (admittedly a huge space for most houses here) but I want to several things with a good length of run between them, and I can do that better with different levels.
     
  12. acptulsa

    acptulsa TrainBoard Member

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    Yes, indeed. It has its advantages too. I guess I didn't express myself well. I respect the way it gives more track in the space available. I just personally don't find it appealing.
     
  13. Maletrain

    Maletrain TrainBoard Member

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    While real railroads run under open sky, the models in our houses are going to run under some sort of ceiling. And, for the most part, we ae going to be looking at the models, not the ceiling.

    I think the key to an enjoyable multilevel layout is to keep the lighting even and appropriately bright on the underlayers. It looks terrible if the lower level seems to be receding into a dark place. But, with reasonable separation in elevations and good lighting on both the layouts and the backdrops for every level, I think it looks fine.

    Operation is another matter. The operators need to use some sort of platform to access upper levels (or else the lower level operators need to kneel). And, two operators can't stand in the same place to operate two different levels without severe interference, especially with the platform for the upper level operator being in-use. So, staggering the locations for operations like switching so that they are not right above each other seems essential for any layout that will have multiple operators.
     
  14. TonyHammes

    TonyHammes TrainBoard Member

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    So bigger is better. Will do a 21" radius will have a helix (6-7 turns) between the upper deck and lower deck and then another 21" radius from the lower deck to Boise staging (6 turns). I will get cranking after I mount some of my old layout frame work on the bottom level to free up some space for construction of the helix
     

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