Bruce,
Yeah, the 2" foam can be hard to find where it's warm, although I've never figured out why. You still need it with A/C on most of the year. Anyway, check smaller lumber yards and you'll be more likely to find some.
Mike Lehman
Urbana, IL
Choops I would omit either the upper frame or the lower frame and use taller risers to get the heights you want. Also the 1/4 inch masonite around the outside edge can be used as a part of the structure, eliminating some framing. The mitered corners are going to be hard to make and not very strong. Use as thick of plywood as you can for the roadbed or you will need more supports to hold it up. Not sure what your track plan is. Have you considered spline roadbed? added suggestion below. 1X4 framing 1/8 masonite around outside edge. https://scontent.xx.fbcdn.net/hphotos-xpt1/v/t1.0-9/481188_10206995309155508_7365743550874556396_n.jpg?oh=293e5eb4fd987a0922379e054b6af763&oe=571D1691 Steve
I would omit either the upper frame or the lower frame and use taller risers to get the heights you want. Also the 1/4 inch masonite around the outside edge can be used as a part of the structure, eliminating some framing. The mitered corners are going to be hard to make and not very strong.
Use as thick of plywood as you can for the roadbed or you will need more supports to hold it up.
Not sure what your track plan is. Have you considered spline roadbed?
added suggestion below. 1X4 framing 1/8 masonite around outside edge.
https://scontent.xx.fbcdn.net/hphotos-xpt1/v/t1.0-9/481188_10206995309155508_7365743550874556396_n.jpg?oh=293e5eb4fd987a0922379e054b6af763&oe=571D1691
Steve
Yes, Steve, I would be interested in spline roadbed, and my research on what it is and how to do it has just begun.
The purpose of the lower frame is to support the layout on the coffee table. The upper frame was thought to provide rigidity. If I use some sort of box or L-girder frame, I'll take a hint from your attachment and offset some of the internal members. Thanks for the picture.
Yes, the mitered corners will be a challenge and will likely have to be reinforced. It's important to avoid knee-busting sharp corners in the the living room. I would hope glued-and-screwed joints with a few gussets would be sufficient.
The first thing I found out this morning is that neither Lowes nor Home Depot have any 4'x8' extruded foam insulation in stock within 100 miles of here (Phoenix, AZ). Another hour or two of online searching for Dow Styrofoam® and Owens Corning Foamular® yielded no local sources.
Part of my original idea was to have a control panel — a 19" x 5½" rack mount panel — set into the fascia:
It would be difficult to mount on a solid foam base, which is one of the reasons I was leanig toward an open frame.
Here's the track plan. Admittedly, it is a spaghetti bowl. This is intended to be a holiday layout for the living room so I can have two trains running simultaneously on the double-track main, which is a double loop (the red and blue tracks) passing over itself. I might even have to put a very small fake tree, 12 to 18 inches high, in the center to promote domestic harmony. All the tracks in purple are for me to sneak in and do some very limited switching when no one else is around. No attempt is made to model a prototype or to simuate realistic operation.
Here in Phoenix we don't have basements, garages frequently get to 120°F during the summer, and my spouse is not inclined to give up an entire room for my trains. So this is about the only choice I have outside of joining a club. At least I could run my N scale equipment on it, while all the HO brass continue to languish in storage bins.
Thanks and Regards,Bruce
Sir Madog Bruce, I do like your enineering capabilities! Option # 1 seems to be very much labor intensive and I think somethink like an overkill for what you want to do. Option # 2 makes much more sense to me, but you can easily leave out one layer of foam without sacrificing on the sturdiness of the whole thing. However, you need to cover the sides with some kind of fascia for protection. It´s a quick solution, but not a dirty one. And it won´t buckle, bulge or warp! It will also weigh much less than you calculated 25 lbs. I bet even less than 20 lbs.!
I do like your enineering capabilities!
Option # 1 seems to be very much labor intensive and I think somethink like an overkill for what you want to do.
Option # 2 makes much more sense to me, but you can easily leave out one layer of foam without sacrificing on the sturdiness of the whole thing. However, you need to cover the sides with some kind of fascia for protection. It´s a quick solution, but not a dirty one. And it won´t buckle, bulge or warp!
It will also weigh much less than you calculated 25 lbs. I bet even less than 20 lbs.!
Thanks, Ulrich. They call me an engineer at work, even though I don't have the degree. I guess the discipline there has been absorbed.
I'd figure on a fascia for either version, so the weight adder is a wash and wasn't included in the calculations.
The four layers of foam was primarily to get the height above the coffee table I wanted, but 2" more or less won't matter much.
The weight was published by Owens Corning rather than Dow, for Foamular 150, as "Approximately 120-130 lb/ 1,000 ft2 for 1" thickness." Foamular 250 is listed as "150 lb/ 1,000 ft2 for 1" thickness." I'm sure there is an error factor in my calculations, especially as I calculated the grade roadbeds as whole blocks of foam before shaping the grade surfaces.
Thanks,Bruce
Thanks to all of you who have replied, and a little more research online, I've come up with two designs.
The first uses 3/8" CDX plywood, which weighs 28.5lbs per 4'x8' sheet, or 0.0062 lbs per square inch. There is also some 1/8" masonite, which weighs 0.0021 lbs per square inch. Estimated weight is 31 lbs.
The alternate design uses primarily 1" and 2" foam. Dow publishes a weight of 130 lbs per 1000 sq. ft. at 1" thick, or 0.0009 lbs per square inch. 2" foam would be 0.0018 lbs per square inch. There is one area of masonite at the top level over a tunnel, which was required for clearance, plus a 1/8" masonite sub-base. Estimated weight is 25 lbs.
The difference calculates to 6 lbs. Other factors include wiring and installing switch machines as Mike Lehman mentioned, and my plan to hang the layout vertically on heavy brackets attached to the garage wall when not in use. I'm concerned how the foam would hold up under tension while hanging, vs. compression when it's set up. So at this point, I'm favoring an L-girder frame, using 3/8" plywood (or even 1/4", which brings the total weight down to 26.4 lbs) instead of 1"x2" pine. I'm considering foam instead of masonite for the "inner and outer" grades, which will also eliminate several risers.
Your thoughts, gentlemen?
A couple of more thoughts on building with a double layer of 2" foam (totaling 4" deep.) You'll want to consider wiring and switch machines (if you plan on using them. You either need to go all the way through the foam (not a big deal with wiring, but switch machines are a little more complex) or staying on the surface for both (shallow trenches for wire with scenery over top once you get it in and maybe Caboose Ind switch throws?)
Unless you must keep the costs to an absolute minimum and are able to do the fabricating yourself, I suggest you investigate the available pre-cut, manufactured sectional systems by Sievers, Mianne and Kam Konnect. They will provide a structurally sound, well-engineered assembly made of quality materials. You can top these with plywood, foam or whatever you choose. Much less fuss and muss.
Dante
Neptune48I think I'm getting in over my head, here. I don't even know which version of foam to use, and a visit to any of the manufacturers' sites boggles the mind with uninformed choices. Looks like I need to do a lot more research.
No, no, I assumed too much. But you did the right thing, ask more questions here, as sometime we old hands assume everyone has more experience than many do and it's very important to help no matter what your experience level.
The basics of foam are simple, although things like the thinner Gatorfoam products get more complicated. For building layouts on, there's two brands commonly available. Both are extruded foam; avoid the stuff made with little beads for structural purposes, although it can be used for filler on scenery if you can stand the mess.
"Pink" is by Owens Corning, "Foamular" is the brand name. It's available in 1/2", 3/4", 1", and 2" although in Southern markets not so much selection sometimes. It sometimes come with a clear film on it now, which you can strip off for better adhesion. The stuff comes in various form factors, like slabs designed for fitting between joists, etc, but most commonly for our use is the good old 4'x8' sheet. Wider than that may be available, but would probably be special order if so. Thus my suggestion on how to make your 60" wide layout work, because usually 4x8 is as big as it is commonly available.
"Blue" is basically the same stuff, but by Dow.
You MUST use foam-compatible adhesives -- or it melts like the Wicked Witch of the West once Dorothy douses her with water. They come in various forms, so what you want to use depends on what you have in mind. The ones in the caulking gun tubes give lots of setting and adjustment time. Contact cements are for making the joint now and getting it right the first time.
Steve's right about the fire thing. Basically a non-issue. And it's made without ozone depleting chemicals.
Using it as I described basically needs no other support, just some protection from dents and nicks with wood sheathing as several have described. It won't sag. In other uses, 2" is fine with a support every 16" or so, although people do go longer sometimes...
Neptune48 I know absolutely nothing about foam, and it scares the heck out of me.
If you're worried about fire, I recall seeing a Youtube video in which they subjected white, blue, and pink foam to a flame. The white foam caught fire. The pink and blue foam just melted without spreading the flame. I tried to find the video but couldn't find it.
Steve S
Henry
COB Potomac & Northern
Shenandoah Valley
RR_Mel I agree with Ulrich, if you’re half as good at construction as you are using your CAD it should be a piece of cake. Mel Modeling the early to mid 1950s SP in HO scale since 1951 My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Thanks for the kind words, Mel. I know absolutely nothing about foam, and it scares the heck out of me. This subject is starting to encourge me to keep my models in the bin where they have lived for the past 30 years or so. Still, drawing the design is intriguing, even if I never produce any physical construction.
Regards,Bruce
mlehman Foam boxed with something light like 1/4" plywood is going to be your best bet for weight reduction. There's one big problem with that... All the readily available styrofoam is in 4 foot wide form factor. So a almost 60" wide square layout is going to require some thinking. If you're OK with deeper foam, you could cut the same design in half, which would make it narrow enough to cut from a 4x8 sheet. Cut two different sets of that from 2" foam, rotate one set so it's 90 degrees from the other and bond them together. That should be strong and stiff enough. There are some other ways to cut and bond it to get your 60" wide layout, so consider the possibilities.
Foam boxed with something light like 1/4" plywood is going to be your best bet for weight reduction. There's one big problem with that...
All the readily available styrofoam is in 4 foot wide form factor. So a almost 60" wide square layout is going to require some thinking. If you're OK with deeper foam, you could cut the same design in half, which would make it narrow enough to cut from a 4x8 sheet. Cut two different sets of that from 2" foam, rotate one set so it's 90 degrees from the other and bond them together. That should be strong and stiff enough. There are some other ways to cut and bond it to get your 60" wide layout, so consider the possibilities.
I think I'm getting in over my head, here. I don't even know which version of foam to use, and a visit to any of the manufacturers' sites boggles the mind with uninformed choices. Looks like I need to do a lot more research.
Sir Madog Model railroaders tend to build the benchwork to withstand an atomic blast, in fear of warping. For a layout of the size you are planning, a rather simple construction consisting of a 5 to 6" Styrofoam board a 1/8" masonite board to protect the sides und the underside is all you need. Lightweight, no warping at all, and dead silent when running the trains. Maybe not cheap, though.
Model railroaders tend to build the benchwork to withstand an atomic blast, in fear of warping.
For a layout of the size you are planning, a rather simple construction consisting of a 5 to 6" Styrofoam board a 1/8" masonite board to protect the sides und the underside is all you need. Lightweight, no warping at all, and dead silent when running the trains. Maybe not cheap, though.
How does one deal with 6" of foam and undertrack switch machines?
Sir Madog,
This looks interesting. I'll investigate price and availablity locally and work on some redesigns.
IRONROOSTER Looks pretty heavy to me. I would buy 2 30" hollow core doors. Cut them at 5', glue a filler piece in the open end. Use foam for hills (Woodland Scenics has some inclines). Join them together when setting up and store them separately. Use 6" sections of track across the joints that you can remove for storage. Good luck Paul Good luck Paul
Looks pretty heavy to me.
I would buy 2 30" hollow core doors. Cut them at 5', glue a filler piece in the open end. Use foam for hills (Woodland Scenics has some inclines). Join them together when setting up and store them separately. Use 6" sections of track across the joints that you can remove for storage.
Good luck
Paul
Paul,
At 2lbs per square foot for hollow core doors, the base would weigh about 50lbs. Weight is a big factor, which is why I posted this question. I cannot find online any good data to calculate the weight of the lumber because there are so many variables, inculding wood species and water content. Either way, I think both my initial design and the hollow core door would be too heavy.
Thanks to all of you. I'll be fiddling with the design now that I have some more good information.
You're getting some good suggestions here, so consider them all because some of this depends on whether you have a pretty fixed idea of the trackplan vs having the option to more easily go back and modify things. This roughly breaks down to foam vs wood for your subroadbed and supporting structure.
I actually do both nowadays. My framing is done as L-girder and the track and supporting structure are wood for the most part. Most of my scenery is now done as foam liftouts.
For something small and intended to be protable, I wouldn't bother with liftouts. You can simply box frame and glue in the foam as rrebell suggested. I have a module like that myself and it's pretty light, would be lighter still if I'd used 1/4" or 3/8" ply as the box. Once glued in, 2" foam make things really strong and is very light. You can then cut and build up the foam as needed. Woodland Scenics offers some foam riser sets, etc that can come in handy if you're not comfortable with building them yourself.
I would still consider using wood for your subroadbed, etc. On the bottom to span and support with the table, you could still use some L- or T-girders. Then cookie cutter your subroadbed to plan, lay it inside your box frame and cut and build up the risers as needed. Once the subroadbed is down you can build foam liftouts to make access easy for wiring etc, as well as allowing you to take scenicking off the layout to minimize mess. However, for something portable like this, I would tend toward gluing in the foam instead for strength.
Another consideration in these chocies is how you'll attach the track. I tend to favor wood because I can drive spikes into it. With foam, you usually glue it down. For something portable, gluing may be better and avoid movement loosening spikes.
My friend made the framework for our portable layout using a grid of thin birch plywood cut into strips about 4" deep. There is a thicker piece around the perimeter. All of the joints are glued and gusseted, making it incredibly rigid. It's not super light, but it's lighter than if it was made from 1" thick lumber. Each section is 60" long x about 38" wide. I'd go this route again in a second.
Instead of plywood on top, I used Gator Foam. In some places I glued it flat and in others I used it cookie cutter style. It's not cheap, but it's much lighter and very stable. It also glues nicely to the wood and adds more rigidity to the layout.
Jim
You can do a boxed frame with a foam topping and I have seen one made out of only foam. I have one 4'x4' module I can lift with one hand and it started as a 1x4 frame with 2" foam. You can sometimes get big blocks of polystyene foam, maybe to the dimentions you need.
Does this mean I should abandon the L-girder design and stick with a simpler box frame? Would you consider cookie-cutter better than spline roadbed?
Thanks again,
Bruce
OK, if that deep, you'd need a 1x10, which would start to make it heavier than you probably want.
Another approach would to to cut the inside supports from plywood, which should make it as light 1x2, but even stronger.
I'm a big fan of making stuff out of 1x2 and 1x3 lumber. What worries me are the large number of joints. Once glued and screwed, the stick lumber can be mighty strong, but plywood would likely be stronger.
Thanks, mlehman.
The benchwork is 8 1/2" high.
Nice set of drawings.
How deep is it supposed to be (top to bottom)?
If it was me, I'd just frame it in 1x4 and be done with it. That's going to save a lot of fitting, as well as being stronger.
Unless you plan on gluing the track down, 1/4" plywood may work out better for the cookie-cutter sub-roadbed. It's will be difficult to either spike or use track nails with 1/8" masonite or other such stuff. The plywood will readily take whatever you spike into it, and resist sagging better.
1/8" masonite will work fine for the sides if you do frame it as drawn. If you use 1x4 lumber it's easy enough to just paint or stain that.