The Helix Part IV …
Well, I completed the first stage of the helix today. All five layers are complete with track. The topmost layer of track has been left a bit short from the end of the roadbed as I will complete this part when I come to merge the helix with the upper deck roadbed at a later date.
The picture above shows the helix at about the halfway stage which was on 13 May.
The picture above shows the helix layers complete with track ready to have the final temporary spacer blocks fitted and then the notched risers. I hope to be able to have this all done by this time next week.
I was amazed at just how quickly it all went all together. I got into a rhythm of gluing the ply sections together, clamping then leaving for three hours. Whilst these were drying, I could lay track on a previously completed roadbed section up to the clamped section. I could lay three sections of 914mm track during this time and by the time I was finished, the glue had set on the next roadbed section, and the process started all over again. Each new roadbed layer was supported on temporary blocks to allow access for clamps. These can be seen in the photos.
Cheers for now.
Posted on May 16, 2012, in Benchwork and tagged helix, roadbed. Bookmark the permalink. 2 Comments.
The way you’ve done the helix, it will be interesting to know if you end up with a slight inward elevating cant on the roadbed. This generally comes from the fact the helix is glued and screwed while it is laying flat like in your pictures. When you put in the spacers, you are changing the elevation because of the different grade. It is like stretching the coil on a Slinky Toy (if anyone recalls this toy from their childhood). Since you have a larger radius helix, the twist may be minimal but on tighter radius helixes, it is more noticeable.
Yes I have read somewhere just recently about that. It may have been on the Model Railroad Hobbyist site. I would think if a cant does present itself, it would be better to have an inward rather than outward cant. Shall wait and see.