Yes
I have a N scale layout I'm putting in an office. It'll have walls on 3 sides. Approximate dimensions are 90" wide and 80" on the longest side. I have a maximum variance of 3" on the outer track to keep with a 2-2.5% grade.
I was wondering if I was over-thinking benchwork for this scale? I was thinking of doing an L-Girder design, and in the attachment, you can get an idea of how I planned on laying it out. Do you think it's wise to go the route of the L-Girder, with it all being open and just having the roadbed supported, or do you think I should just build flat tables and use foam to build my slopes up.
The flat table route would be MUCH faster, but I was wondering if someone could speak from their experience here.
Webnerdnick;
I think you may indeed be overthinking the benchwork for such a small layout. I should explain that I'm a big fan of L-girder construction to prevent warping, and I often promote it here, and I also use it on my own layout.
However, your layout is going to be in an office, which I'm assuming, is climate controlled. That should minimize the warping, though it won't necessarily eliminate it altogether. The type of wood used, and whether or not it's painted, would also be possible warping factors.
The other advantage of L-girder is its great strength, especially over long spans between table legs.
It is also lighter weight than some of the "really overbuilt" (and underthought) benchwork we see here, A 2x4 grid topped by 3/4" plywood, supported by 2x4 legs!
For the size layout you will have, and the minor weight of model trains in any scale smaller than the live steam, you can ride on it, type, the strength is not needed.
CTValley and I agree on most things, and I think we may, at least in part, basically be recommending the same thing here. A thick sheet of extruded foam.
The supporting structure can be L-girder, but it doesn't need to be the traditional, heavy-duty, 1x4 and 1x3 type.
I use a form of "L-girder" (or "C-girder") made of the 1/4" Luan plywood that I use for sub-roadbed and 3/4" x 1/4" pine strips glued under each side of the Luan. (see photo #3) I'm not suggesting you go that small, since the "span" between my risers is rarely more than a couple of feet, but there are inbetween sizes. My "benchwork" is weird, made up of foam-filled box-girders and arches, supporting a bookshelf top. (see photos 1 & 2)
You also won't need the "stringers" or cross pieces, shown in your diagram, or at least not as many, if you use 2" foam. The cross pieces you do use can also be built between the L-girder outer frame, in a grid. That saves thickness, which is one of the disadvantages of traditional L-girder construction.
My old club used 1x3 & 1x2 L-girders as a basic outer frame and added 1x3 stringers inside this frame in what amounted to open grid benchwork with an L-girder outside frame. The entire benchwork including stringers, was only 3" thick.
Any of the benchwork types we've discussed in this thread, traditional, heavy-duty L-girder, smaller & modified L-girder, or open grid, will work well under a sheet of thick foam. Any will give you the necessary strength to rigidly support your layout, and yet allow you to have the convenience of a flat surface that can be carved downward as scenery demands.
Good luck, Have fun;
Traction Fan :smilie_daumenpos: