You can use beaded foam too and no ply, no it is not messy unless you try to cut it with the wrong things. Beaded foam can be had for free at times. Also build it in sections bolted together with nothing bigger than 24" x 50" so it can fit throgh doorways easily.
I did not use a plywood top at all. Instead, I built a simple box frame from 1x4 and 1x3 lumber. I made the legs from 2x3s, and scrap plywood for the triangular gussets to stabilize the legs.
This is 5x12 feet. I put casters on the legs so I could roll it around.
The legs are held on with wood screws, so it was easy to detach them to move this whole assembly inside. Once there, I used 2-inch pink foam as the layout base.
Pink foam is very lightweight and quite stiff. It easily supports trains and scenery without bending. It is not affected by humidity, heat or cold. What it can NOT do is take a person's weight, so it's not suitable where you might have to climb on the layout. It also won't hold nails or screws, so laying track is something that's done with glue.
It takes an iron man to play with a toy iron horse.
My main peninsula is about the size you intend to build (actually a little longer) using steel stud 'C acts like L' girder construction and cookie-cut plywood subgrade supported by risers made from steel stud material. (I'm a lot better at creative tin bending than I am at carpentry.) When it was free standing I could lift one end with one hand - and I am NOT Hercules.
I have found that 30 inch reach-in is not comfortable, but it IS doable - for scenery construction. I've kept the tracks closer to the edge, not over 20 inches. The end curves are concentric 24"/26.4"/28.8" (actually 610mm/670mm/730mm) with safety rails. The visible track above them has curves under 14 inch radius (350mm) but that's on a line laid out by following a mountain goat up the canyon.
So far I haven't had much trouble building or operating the monster, and I'm closing in on my 78th birthday (and need for a replacement hip...)
Chuck (Modeling Central Japan in September, 1964 - from my own field notes and photos)
Ed's suggestion about making open grid benchwork, with the roadbed cut from plywood, will likely get more mileage out of a sheet of plywood, but if you're set on a tabletop-style layout, use 5/8" flooring plywood, good-one-side. This has tongue-and-groove edges, making splicing much easier as the joint requires no more support than the rest of the sheet if the joists are run at 90° to it.I used it when building the partial second level of my layout, most of which is 30" wide, and it saved me the cost of at least a couple of sheets.
Wayne
Rather than using the "table-top" approach you might want to consider open benchwork and cutting your plywood roadbed to fit the track plan.
As others have mentioned, having an idea and trackplan first allows you to customize the benchwork framing and the roadbed is then cut with an allowance on either side to bring the scenery in to it.
This method is less flexible as far as design changes but it allows for over & under track layouts and avoids the dead-flat prairie look unless that's what you want to model. You can allow for city and railroad yards using smaller scraps of plywood.
There is the "cookie-cutter" option as well but this also calls for pre planning the track layout.
Call me old fashioned, but personally, I would skip the half-inch foam layer. Homasote, yes—foam, no.
Keep accessability in mind, too. As you get over 48" it is a pretty far reach to the center. With open grid you can design a "pop-out" or lift out section toward the center where you can stick your body up through the layout to access inner areas.
Try not to be in too big of a rush without looking at all the options. Ed
Main isle looking north. West Blob is to the left (6' wide x 18' long), East Blob is to the right, it is two ping pong tables (home made 5x10' each).
East isle looking north, East Blob is not to the left of me and the three deck wall line 16" wide x 24' long is on the right.
The middle of the West Blob is show above. It is 6' wide, but the middle, where I can not reach anyway is left empty. We are now looking south, to my left are three levels (South Ferry, Smith 9th and Times Square) and to my right are five levels (Courland St, Nevins Street, Lenox Avenue, 8th Street, and Coney Island on the top).
Cats like to think vertically.
LIONS are not very fussy about structure. The Nevins-Lenox loop is built on 2" thick fiberglass insulation board of the sort used by roofers, proped up on some 2" foam blocks. Above that is the 8th Street - 42nd Street loop, it is built of 1/2" Celotex with that lone prop in the middle which is a stick of the 2" fiberglass sheet stuck on end.
LIONS do not build pretty, but they do build cheap. Most materials were found as scrap on job sites.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
MikeyChrisI had thought about splicing plywood to get more than 4' width (I really want at least 24" radius and an inch or more between track and edge of layout), but the reinforcing required for the splices kinda messes up the plan.
I apologize if I don't clearly understand the concern about splicing but I'll add some thoughts. Firstly, I'd encourage developing a track plan for your space and then build what's needed to support it. If that means a 4-1/2 x 10' rectangle you can build the support structure from 1x4s with joists & 4 legs, and add plywood and foam atop that as you desire. You can add splices where needed along seams, skipping it at joist crossings as needed. Just ensure that any joint areas that will be below track are nice and flat (sand as needed), and adjust joist spacing as needed to have splicing below such spots and also consider joist locations where you will have turnout throwbars for ease of switch machine installation if under table type.
I built a 5+ by 10+ ft HO layout, much wider than recommended for reach purposes. I could have installed an access hole in the middle but put a yard there instead. Do consider having the layout legs on wheeled rollers. I mimicked a layout frame described in the 4x8 Virginian project. With 1x4 framing, you can have legs inside the cantilevered legs such that the span between legs is about 8'. I used 5/8" plywood since I planned cookie cutter elevation changes and wanted some good stiffness between risers.
I do encourage providing all the space you can between the track and the edge but also maximizing radii, which becomes a compromise. Determine whether you plan to have a backdrop at the back or access without reaching over one.
Let us know more about your track design ideas and perhaps we can add more thoughts.
Paul
Modeling HO with a transition era UP bent
First, I would recommend 1/2" plywood unless you are going to have your cross pieces only about 12" apart. You would be surprised how easily 1/4" plywood sags.
You can make a 4.5' by 10' table top out of two standard 4' x 8' sheets. I would cut one sheet lengthwise down the center resulting in two 2' wide pieces. The other sheet I would cut lengthwise at the 2.5' line. resulting in a 2.5' piece and a 1.5' piecs. Use one of the 2' piece and the 2.5' piece for your table top, splicing it down the center. You will have plenty of scrao to use for splice blocks on the underside. Use 4.5' of the remaining 2' wide piecs at the end of the 8' pieces to make your table top 4.5' x 10'. In addition to splice blocks you can cut the remaining scrap into 90 degree triangles to use a bracing for the table legs.
As for the weight, if using 1/2' plywood makes it to hard to easily move, try some furniture moving pads. We have several and find we can easily move heavy furniture, washing machine, etc.
Good luck!
Hello,
After a 30 year hiatus, I am going to start another layout. Due to space constraints I am pretty well restricted to an island layout about 4 1/2 ft wide and 10 ft long. I was considering using a grid frame with 1/4" plywood tabletop, covered with 1/2" insulation board (I live in the South and 1/2" insulation board is all I can get - I can use more layers if needed). This seems to be the best compromise between:
1) getting it running
2) lightweight (so I can move it around as needed)
3) still strong enough construction to allow 2) above
I had thought about splicing plywood to get more than 4' width (I really want at least 24" radius and an inch or more between track and edge of layout), but the reinforcing required for the splices kinda messes up the plan.
Any suggestions? I really need to get the ball rolling so I can run some trains for my grandkids (and to keep my interest up). Thanx to all and Happy New Year!