Hi:
I am thinking about my first attempt to build a helix in HO to raise the track about 20 inches. The helix will be circular with perhaps 2 short straight sides. I have seen many suggestions and even a commercial kit system. I remembered reading about a plan to build the benchwork using trapezoid shapes rather than the more traditional curved shapes. An advantage of the trapezoids is that you can cut them from a 4x8 piece of plywood with straight cuts and a minimum of waste. Now for the life of me I cannot find this article which I think appeared somewhere in the wider MR domain within the last 2-3 years. Can anyone help me locate this writeup of the template for the plywood cutting template? Searching the MR site didn't help.
A trapeziod , by the way, is a 4-sided shape with 2 opposite sides parallel with each other.
Many thanks for anyone who can help, or has experience and tips for helix construction.
Alan
Hi Alan,
The information you are looking for is in the Decenber 2004 edition of "Railroad Model Craftsman" on pages 88 to 90. This shows you cutting diagrams and such. I think the only thing you have to figure out is the width of the pieces in regard to the number of tracks that you will have on the helix.
The title of the article is "Octagonal Helixes"
I used this several years ago and mine is a 4 1/2 turn helix with only a single track as I am a lone operator and there wouldn't be a time when I was running one up and another down at the same time.
It has worked well and I have been pleased with it. I wish you the same success.
By the way I used threaded rods rather than blockes of wood for support, much the same as Mark Bruton did. If you use the search button on the bottom and type in Helix you will find lots of hints and tips, and probably even the pictures of Mark's (Behumouth) (I think he calls it) Helix.
That magazine is "Railroad Model Craftsman" Not Model Railroader.
Johnboy out....................
from Saskatchewan, in the Great White North..
We have met the enemy, and he is us............ (Pogo)
Thanks John for the rapid reply. This is great - my first experience in getting help from the forum resource. I will have to see if I can find a copy of the magazine you are referring to. I would very much appreciate any link or electronic copy of the article if you know of one.
Alan, this is from another thread, but you might find it useful.
-Railpub.com has an excellent selection of back issues for sale. It's not the cheapest way to go, but it is quck and reliable. Nice to do business with.
-Back issues of that vintage (and much older) show up regularly on eBay. Sometimes you might have to buy a whole year's worth to get the edition you want, but still at reasonable cost.
-Most train show/swap meet events have vendors with the more popular mags (like MR) in good quantities.
Whichever way you go, you should not have much trouble finding one. Good hunting!
Long Live the "Wobbly"
You might consider rerailers for the short straight sections as a safeguard. These straight helix sections can also relieve stress upon the couplers that would be greatly heightened by nothing but a curved track helix.
P.S.: Don't forget to do a forum "helix" search and then be prepared to bookmark.
Conemaugh Road & Traction circa 1956
Alan,
Check out this link. Hope it is usefull to you.
Octagonal Helixes
Also the following link about 1/3 down the page...
Helix Module
Thanks, Kevin. I am not a wielder but appreciate the implied need for a very rigid structure. A steel frame would seem to be bit of overkill for the stresses and weights involved but if you like wielding then I guess this is the fun way to do it! For me I am a wood-worker so it will be plywood, glue and screws.
I am thinking that perhaps the easiest approach is to build the helix and frame separately from the layout. Incorporate the track and wiring at each level as you proceed with the construction. Test the final result with some running consists. Then put the whole thing into the layout - having first made an adequate space and connection links. The last step looks like it would need 2 or 3 people to do the lifting and lowering. Is this how it's done?
I also used steel rods with nuts to hold everything in place. It's very solid once you tighten everything down. I used 1/8 plywood doubled-up to 1/4 inch and everthing seems pretty good. I haven't finished my lower level (or even started really), but the helix is complete waiting for the upper level to bring the goods.
-T
A friend of mine built 3 helixes, 2 using the octagonal (trapezoidal) and 1 using arcs of plywood. The octagonal method used more plywood than the arc method for HO. There were also more joints and they were longer. The arc heliz was more "rigid" and had a naturally smoother slope.
Both styles used a threaded rod to support and adjust the grades.
Dave H.
Dave H. Painted side goes up. My website : wnbranch.com
Here's how I built my helix:
http://www.thecbandqinwyoming.com/CM%20-%20Behemoth%20Helix.htm
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
Thanks for the link, a great step-by-step for helix construction. I am surprised that cutting curves rather than octagonal pieces uses less plywood [other post], but appreciate that the curve method will produce a more rigid structure. I plan to build mine up from the base benchwork and not hang it from the ceiling. I assume that the basics of your method will work fine with this. I also need to get inside the helix for "maintenance" [derails etc] - up from below the base benchwork. My track radius will be 44" and the elevation about 20." Since I will be building a helix with about 18" if opposing straight sides, I figure I will only need about 4 tiers with a fairly moderate grade although I haven't calculated this yet. Should I do twin tracks - just in case of expansion in the future?
Another idea I was toying with was to build one half of the lowest tier outside of the main helix confine so as to do a bit of scenicking on the edge of what will be a large mountain when it's all covered in.
alanprocter wrote: My track radius will be 44" and the elevation about 20." Since I will be building a helix with about 18" if opposing straight sides, I figure I will only need about 4 tiers with a fairly moderate grade although I haven't calculated this yet. Should I do twin tracks - just in case of expansion in the future?
Since my friend built the octagonal helices, I made an Excel calculator to determine the size of each piece depending on the radius and how much clearance is desired from the track center to the edges of the piece.
Based on my calculations, with 44" radius, allowing minimum of 2" on the inside and 2" on the outside of the pieces, each piece of the helix will be 7.2" wide, with a long side of 38.11" and a short side of 32.15". If you increase the clearance to 3" inside and outside you will have enough room to put double track and you piece size increases to 9.12" wide with a long side of 38.94" and a short side of 31.38". That will make the center line of both tracks 44" radius, if you have to have 44" minimum radius, then the centerline of both tracks will be 45" nominally and the piece sizes will be 9.20" wide, 39.76" max and 32.15" min.
When you try to make an angled cut on the ends with a piece over 9" wide, you will have a cut longer than a chop saw can make, you will have to cut them with a table saw, radial arm saw or a handheld circular saw.
I can't post the spreadsheet to the forum, but if you send me a PM with your e-mail address I will send the Excel calculator to you.
Oops! How I wish I had the room for 44" radius! This is the diameter - the radius is 22."
width = 6.45" Long side = 19.88" Short side = 14.54"
For a double track with 2.5" track centers, min radius 22", 2" clearance inside and out:
Width = 7.56", long side = 21.95", short side = 15.69".
There is another option. Instead of using the plywood you were going to use, buy plywood 1/2 the thickness. So it you were going to use 1/2" ply, buy 1/4". Then cut arcs out of the 1/4" ply and glue the arcs together with staggered joints to form 1/2" plywood. Requires a lot of clamps. Advantages are you have no "joints", you have no splice plates, the helix has a smooth continuous structure. It is harder to do well with wide pieces because it needs more clamps.