Helix Construction

[Anonymous]

I know what a helix is and I can probably do the math to get the specifications, but are there any resources that suggest ways to build one?

[claycts]

Research the MRM issues they have had a few. The "OTHER" one had an article last year. Whole key is the radius and the support of the helix to clear the rolling stock. I went with a NO-LIX easier to fudge and make work.

[Adelie]

I found a helix calculator somewhere that will do some basic calculations. It has fields for the radius, number of turns, overall height, and whether you are using coarse or fine numbers for your inputs (coarse is to the nearest inch or percent, fine is to the nearest quarter of an inch or percent). You provide those fields and it will calculate the grade and track required and clearance between levels. I'm sure I was found it in a thread out here, but I can't find that and didn't notice it on a Google search.

If it sounds like something you want, drop me a line and I'll email it to you. It is about a 400k Windows executable file that zips down to around 200k.

[DMNolan]

There is no one right way to build a helix. How much space do you have and how much separation will be between the bottom and top of the helix? On my layout, I built two helix, one on top of the other. I cut allot of plywood to build this monster. I used 1x4, cut and laid sideways as spacers. Once I got my first level grade worked out, I had a constant grade on all turns. Here are two pictures that might help you. The first is just the helix down to lower staging, which descended 12". The second photo shows the helix to the upper deck, on top of the first. It climbs about 22" to the upper deck. The helix are large, about 7' across with wide radius. I figured the grade at one point, which was less than 2%. I have no trouble pulling long trains up the grade. Try to keep your grade low and your climb constant. On my previous layout I did not double track the helix and it created a bottleneck for operation, so if you space allows for it and it fits in your operation plan, double track it now. You don't want to build it twice.

[Big_Boy_4005]

Mark, I like the spacer block method too, and used it on my O gauge helix.




The math is: height gain per 360 degrees (rise) divided by 2 pi radius (run). The result of the calculation expressed as a percentage.

Height needs to be railhead to railhead allowing for clearance in your scale. Maximum percent grade should not exceede 4%, 2% is practical.

There is a construction technique that uses threaded rods and nuts, which works well. Spacer blocks are just cheap and easy. Of course you lay the track as you go.

[pcarrell]

Maybe this will help...

http://anemrr.ejpj.ws/Seq02.htm