# Anyone made a helix?



## Randy Stone (Jan 2, 2008)

If I had the room I'd love to put an 8 or 10 foot diameter helix together to drop from my table height of 42 inches to ground level. Figuring that you would have to allow clearance for most eveything except maybe 1;20.3 stuff, what would the grade end up being? It could even be a dobble track with one line going up and the other going down. Any thoughts or ideas?


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## Semper Vaporo (Jan 2, 2008)

Well... thimking whilst I is typing...

Assuming the loops of track are directly over each other, then the clearance from one to the next has to fit a train. That distance has to include the thickness of the roadbed and track, and the height of the tallest train. Assume 8 inches for the train and 2 inches for the roadbed (that should be plenty and probably could be reduced!) that is a 10 inch change in elevation per loop, so you need 42/10 = 4.2 loops to drop 42-inches.

With a 10-ft diameter, you have Pi (3.14159) times the diameter for the circumference, so you have a distance of of 31.15-ft (or there abouts) per loop and 4.2 times that distance is, ummm... now I need a calculator... hang on... 132 ft. or 1583 inches... so the "Rise over Run" = Grade is: 42/1583 = .026 * 100 = 2.6 percent grade.

You may have to adjust the number of loops, or fractions thereof, to get the start and end points to come out to a useful place on the layout and you may alter the elevation per loop to fit your equipment and structural components.

Of course, if you make the helix a spiral where the higher sections are not directly over the lower sections then you remove the height requirement and can make many more loops that vary in diameter, but you could reduce the grade considerably that way. Calculating the length of a spiral is beyond my feeble brain at the moment, but I bet there is a website that could be found in a google or bing search that would tell us how.


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## Randy Stone (Jan 2, 2008)

Well 2.6% grade isn't bad at all. I was thinking it might be as much as 4%. 

If I were to build one, it would be a straight 10 foot dia outside spiral with the 8 foot spiral heliix on the inside. So the tracks would be directly over top of each other. 

This would make a great mountain RR with a mine on top.


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## Greg Elmassian (Jan 3, 2008)

I tried a 9' diameter helix for 21"... no way... I could ALMOST make a loco go up and down, but no cars... got the RS3 to traverse it eventually... 


Read here for my experience and notes: *http://www.elmassian.com...trong>**








*


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## Dick413 (Jan 7, 2008)

Your looking for something like this


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## Randy Stone (Jan 2, 2008)

Yea DIck 

That looks cool. 

Thanks for posting.


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## Randy Stone (Jan 2, 2008)

Greg 

I can understand not being able to pull long trains up the helix, but why can't you take a long train down? 

What was the grade of you helix? 

Did you see much wheel slip going up?


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## K.A.Simpson (Mar 6, 2008)

Try www.StansTrains.com. 

Have look at his handy converter, which has all the variables about construction of a helix, distance, rise, amount of track needed, spacing, area needed to biuld - amongst lots of other items about garden railway construction. Well worth the very few $ to obtain. I found it lived up to what was advertised. 

I might add I have no connection to this business apart from being very happy with this product. 

Andrew 
Sandbar & Mudcrab Railways


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## Pete Thornton (Jan 2, 2008)

I did a Google search using "site:mylargescale.com helix track " and came up with a few threads. 

What didn't come up was the long discussion with Quinton (?), the owner of Train Mountain in Oregon, who asked about building a helix for access in/out of his storage shed. (Does anyone else remember?)


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## Greg Elmassian (Jan 3, 2008)

I was looking at clearance issues, i.e. being able to run taller cars, so I could not get the right number of turns and the track to track spacing. 

With those constraints the grade was too much, over 5, I think closer to 6. 

Also, this was on my main line, so I wanted to be able to run a 30-40 car train through, and go both directions. 

Stringlining going up was a problem, getting good transitions from level to grade too. 

Down seemed a lot easier, and I have a 5.5% grade about 60 foot long and manage keep cars on the track even with a lot of pressure, so short trains and downhill would most likely work, even with the strong grade. 

Dick's allows more turns and less of a grade. You can see that my space was greatly constrained, I could NOT put another 360 degrees of track in that space. 

Greg


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## fyrekop (Sep 20, 2011)

In the "If I'd only Known" section (page 90) of the Feb. 2012 Garden Railways is an article about building a helix and finding out larger scales didn't fit. The author, who lives in Pinetop, AZ, wanted to go up 2' in less than a 2% grade and included his calculations in the article. Worth a look if you happen to have an old copy laying about he has a couple of good photos too.


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