Files related to building a model railroad helix. This is a simple to use calculator to aid in building model railroad helixes. I personally built a dodecahedron (12 sided) helix. My building technique involves inverted trapizoids that overlap. The layers are made into a two layer laminates.
Enter the number of sides you wish, and the midpoint radius of the external boarder and internal boarder. The spread sheet does the rest.
The default values are for a docecahedron with an outside diameter of 38" and an inside diamemter of 30". Just change the three values on top for your desired dimentions.
The lengths of the short side, long side, hypotnues, and tail length are to aid in cutting your building material. The short and long sides are parallel and the hypotnueii form the other two sides of the trapazoids. The length of the "tail" is the cut off above the first hypotnues. For a docecahedron (12 sided) helix the angles of the trapazoids are 30 and 150 degress. You could set your saw for these angles or measure along your stock and connect the points.