Another problem : for those among You who use Rokuhan, do You mount the ballast parts "firmly together" or do You leave a gap for expansion of the rails ? With other terms, is the gap already calculated in the length of the rail to allow dilation when ballast parts are jointed ? I want to fix my tracks with screws on plywood, but I think that with the present temperatures the rails have already reached their maximum length ... And even if temperature is increased by 10 degrees, this would only make less the 0,2mm per meter ... (0,18 exactly).
Post by Greg Elmassian on Aug 3, 2017 10:37:32 GMT -5
I'm not going to get into an extended argument, but glue your track down, it will provide a little "give". There's TONS of reasons NOT to use screws, like no ability to expand/contract, distorting the track, etc.
Also, lay the track when it's warm, not hot or cold, like the real railroads.
I found 1.4 mm "Phillips" screws (I saw they are the same as Märklin 7599, unfortunately more expensive, so I think I will use Märklin ... Thanks ! ) and from Tamiya the same colour as the Rokuhan ballast ; I tested and at 20 to 30 cm I couldn't almost notice them ...
Last Edit: Aug 3, 2017 15:02:46 GMT -5 by alberich
My first layout was Marklin track nailed through a cork roadbed into plywood. I had a number of problems with the track, primarily due to changes in the wood base due to humidity changes. What I would suggest is one fastener per track section, midway in the section, leave the fastener loose enough or enlarge the hole in the section such that the track section has a bit of movement. No fasteners directly into turnouts.
Not sure this is all you need, but my next layout, but to these rules, operated much better.
The problem is that I would have to put a brace under every section of track : if I insert my screw directly through the ballast in the middle it could cause deformation ; Rokuhan has two places (with braces) per section for screws. I calculated that the variation in length per straight section (220 mm) and 20 degrees would be less than 0.1 mm (0.08mm) ... So I don't know if temperature is THE real problem. My layout will be in an insulated room in my cellar and the carpenter used poplar plywood for all parts ; I hope it is a good quality which won't undergo too much deformation ? Under the tracks platform (26 mm wide, thickness 5mm) there will be a shelf every 12.5 cm (8 per meter with 2 mm difference in height, 1.6% ). For my former (N) layout I used the same structure and the Arnold (steel) flex tracks were nailed through each hole. I never had any deformation, only ... RUST ! If necessary, I could use anti-dampness "flakes" (only for the wooden structure, this time ? ). Or perhaps I should varnish both sides of the track platform after assembly of the structure, and before screwing the track and ballasting left and right from the track ?
Last Edit: Aug 3, 2017 16:34:23 GMT -5 by alberich
Everything is going to expand and contract with temperature and humidity changes. It's not how much one expands or contracts itself, Its how much the difference is between all the materials used is. Have you figured out how much the plastic roadbed is going to change or how about the wood base have you taken that into consideration?
Make sure the wood your using for your base is DRY before painting / sealing and assembling. Most Lumber from big box home supply stores is not dry when you buy it. While you may pick it up off the rack from inside the store when you buy it, it is usually shipped on a rail car then a open bed truck subject to all sorts of weather conditions prior to reaching the store. Believe me the plastic wrap its covered in for shipping is ripped torn and has holes in it more often than not allowing it ample time to soak up moisture from rain and humidity long before it reaches the inside of the store. Damp Lumber Will Shrink over time as it drys. Let it lay flat in a dry low or better yet no humidity location for a few weeks too a couple months till its good and dry before getting started with your track work and scenery.
Post by Greg Elmassian on Aug 3, 2017 20:19:09 GMT -5
How did I know that my suggestion not to fix the track tightly would be immediately rejected?
Also, if you put screws loosely nothing will be deformed, "brace or no brace". That is the key, don't deform the plastic... know anything about "cold flow" in plastic?
So, the single screw suggestion is rejected, even though "braces" should not be a factor.
A flaw in your calculations, or at least something missing.... the expansion rate of the rails is not the same as the plastic. If temperature was really a factor, there is your issue.
So, I've laid a lot of Rokuhan track (we built a multi track switch yard a scale mile long on 3 modules and transported it to many shows in all kinds of temperature. Track stuck with 3m adhesive film.
My vote is with David, the humidity and possible shrinkage of your base will be a bigger problem until you equalize the moisture in the wood with the average humidity in the room.
Again, I think you are overthinking this in a dimension you don't have to worry about (temperature in your train room).
Butt them firmly together, use glue (the tacky glue we use comes up easily, not all glue is permanent), no screws and season your lumber. If you must use screws, don't screw every section, but maybe you will have to if you do something other than loosely.
The only "lumber" is the frame under the base plate (planks 22 x 100 mm) and, when I will begin with building, then it will be at least 3 months old (it was assembled and delivered by the carpenter in the very first days of May) ; the other wooden parts are plywood, when assembling there will be at least 3 weeks I got them FROM THE CARPENTER. I read plywood is more stable than "lumber" due to the glue and I think probably better protected during transportation. And one must add the time it was stored in the carpenter's and the wholesaler's rooms ... I don't work with LUMBER directly bought from the shelf. So, Tjdreams, thanks for Your ideas, I followed Your recommendations without knowing them ! For the scenery, I will use "Roofmate" (I think the name is the same in USA ? ).
Last Edit: Aug 3, 2017 23:27:17 GMT -5 by alberich
Post by boxcarwilly on Aug 4, 2017 10:10:12 GMT -5
Oddly enough, this was the very first question I asked myself when I first got into model railroading many, moons ago, and as I was told then and later read up on, a foam base on a wood frame seems to be the standard accepted by most model railroaders for many reasons including expansion and other temperature related problems. All of my layout is built this way. I use Woodland Scenics risers on the 1 1/2 to 2" Styrofoam base and all my tracks are fastened with straight or dress making pins. I've done it this way just for the purpose of easy and quick removal to replace turnouts, track or change the design. Of course for those sections that I consider to be final, I have added ballast along both sides like the prototypes and that is held down by a special glue mixture. It all comes back to personal preference. I've never considered gluing or screwing tracks directly to a wood base, but I suppose it has it's merits.