Getting back into HO layout building after too many years away. I passed on or sold 90% of my old stuff including MR collection of many years worth of magazines. I recall back in about the mid 80s or early 90s an article about making a helix using basically straight strips of ply with the ends cut to specific angles and then joined into loops to form the helix. Anyone recall this article or know were to find it or if the back issue would still be available?
For some reason I don’t have that issue on hand to check for sure, but according to the MR magazine search you might be looking for “Octagonal Helixes - Easy to Lay Out, Eliminates Waste” in the December 2004 issue of Railroad Model Craftsman: http://trc.trains.com/Train%20Magazine%20Index.aspx?view=SearchResults&q=helix&startYear=1995&endYear=2012&magazineId=2&advanced=true
And here is some additional info that seems to confirm the issue I mentioned above and claims it has a calculator to help you with the dimensions: http://groups.yahoo.com/group/ldsig/message/68288.
I like the trapezoidal-section helix idea. I have three on my layout constructed this way. Measuring and cutting are much quicker than with curved sections, and there is considerably less waste.
Here’s one of them, with the helix located within a turnback curve at the end of a peninsula.
Rob,
I generally agree with your points on the advantages of the trapezoidal method. Having worked with wood, I suspect when you said that “measuring” was quicker, it’s because you’re an experienced woodworker, too. Nice benchwork!
One caution I’d have is that the trapezoidal method does require more accurate measuring and cutting to get good results than cutting circular pieces, which tend to be more forgiving of slop in measuring and cutting. Depending on one’s comfort level with woodworking, the circular method may be easier for some. However, if you can measure and cut carefully, the trapezoidal method has a lot of advantages.
I doubt it would be this article as I was totally out of the hobby at that point and seldom bought RMC magazines due to their scarce availibility up here in Canada but this could be a good place to start thanks …
You might be correct, but I could not come up with anything else using the magazine search. It is possible that there was another article which covered the subject, but didn’t have helix in the title.
Anther place to look might be in one of the Model Railroad Planning books published by Kalmbach.
My experience in woodworking isn’t that extensive. What I noted with trapezoidal helix construction is that a high level of accuracy isn’t critical. If you can lay out the pieces into an approximate octagon (or whatever shape a full “circle” of your trapezoids should be), they’re close enough. I have some gaps at most joints. Having built with both trapezoidal and circular pieces, I found the trapezoids more forgiving of slop.
Thanks, but don’t look too close!
You may also want to check out Doug Gurin’s “A primer on helix design” from Model Railroad Planning 1997. This article is also available in the Information Station download Guide to helix and staging design (vol. 1).
Hope this helps,
Dana Kawala
Senior editor
Model Railroader magazine
Since my favorite helix material (steel studs) comes in straight form only, I have laid out helices with various angles and various lengths (and numbers) of sides. Th best method is to draw the radius desired (either full size or in scale) then check how much of an arc can be put on a single straight piece of your subgrade material. That, in turn, will determine the angle of cut, the number of sides to the geometric figure (HINT - Shoot for an even number) and the complexity of the build.
So, where do you put supports? At the extreme angles of the corners and at the center inside of each straight section of subgrade. I leave figuring desired grade, and exact heights of supports, as an exercise for the student…
Chuck (Modeling Central Japan in September,1964 - with helices)
I will point out the one thing that that for some reason isn’t always obvious - once you calculate your grade and the amount of rise needed, the length of each support is IDENTICAL. The only ones that vary are for the first turn going up. After that - all the same.
–Randy