Looking good!

Dear Greg,

Looks good from here...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

​PS if this will be moved around regularly, you may consider adding some wear-plates along the bottom edge...

Foamcore music

Greg,

I've been using foamcore bases for demos for Clinic presentations. Depending on your use, you might want to take steps for sound deadening and reinforce the top, otherwise you may hear your baseboard instead of simply seeing it. The resonance can be quite noticeable.

Best regards,

Geoff Bunza

Wear Plates

I have thought of that. It will be moved fairly often as my work desk will be its operational home and I need to work sometime!  

GregW66

Exciters

Dear Dr Geoff,

If using exciters as "layout sound speakers", the light thin resonance can be tuned (not a typo) to one's advantage...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Well hell , I thought I

Well hell , I thought I finally had an orrigional idea .LOL Started an 8' x 1' module a month ago using this idea. My top is 1" blue foam with foamcore as the frame . I used hot glue to assemble mine . Its for a small HOn3 switching module I'm working on . I have the track laid on cork and there are no noise problems ....Mike

Legs

I'm really impressed Greg, with the construction of your module.  I have been thinking of using Luan plywood on a future build but I'm going to follow yours first.  Construction sure looks a lot easier.  Looking forward to seeing how you will attach the legs.

Foam core issues

I have been experimenting with foam core base structures for about two years.  Some have been like these, ladders, some have had luan side panels and so forth.  Your workmanship, very neat, is better than mine.

i like to see what others are doing because none of my efforts has been wholly successful.

Humidity has been a problem.  I live on an island off the east coast, and white foam core starts warping as soon as I pull it out of the Subaru.  The warping can be managed in small applications like structure sub-walls but really begins to add up in larger pieces.  The styrene foam is stable, but the surface paper

Black foam core, which I buy from Dick Blick Art Supplies, seems more stable and is available in thick sections, up to an inch or more.  You can also remove the paper from both sides by spraying it with wet water, and I use the inner core a lot for building foundations and other "concrete" applications.

But I digress.  My second problem is that I want to build baseboards in vey thin sections.  

I can get thin sections from foam core that work fine on tabletops or desks or standard benchwork, but they are too floppy longitudinally to be usefully portable.  They bend when moved, sometimes enough to pull track apart.

i am currently experimenting with composite foam core-luan-3/4 pine structures with some promise, and I have other ideas involving ultralight beams.

None of this is my main focus, but like many people my age, I go away for the winter and want to take some model railroad along.  The challenge is building something fun to operate that will fit in limited space in the car and condo.

So I hope others will continue to post their efforts, and I will try to get pictures of some of my efforts, successful and not so successful.

I've used Kappa Board (foam core) ...

... in my modules.  I also live on a tropical island and have had no issues with warping.  The paper skins are a bit like poster board, they are slick and somewhat water resistant ... I have gotten water on them and it doesn't soak in.

For best results, I think you want the joints to be clean, close-fitting, and tight for 100% bonding to create a semi-monolythic structure.  Notching the pieces (egg-crate style?) makes for very strong joints as well.  When building a simple frame with a top, it will be subject to twisting ... another skin on the bottom would probably prevent that (same as a hollow core door) but then access under the top surface becomes rather awkward.

I've built a full proscenium module and after attaching the backboard/skyboard, the whole module has become incredibly stiff ... really, no twisting at all.  Professor Klyzir has provide some good links to foam core construction about 4 posts from the top of this page:  https://forum.mrhmag.com/post/portable-oscale-layout-aka-chicago-fork-12196898

Foamcore excitement

Hi Prof,

Given a "box" of the base frame that might be relatively clear, is it actually possible with an exciter to use it for background layout sound? Never considered that! Could be very useful. Any guess as to frequency repro characteristics?

Best regards,

Geoff Bunza

This project has no legs!

I intend the module to be operated on my desk. That's why the Professor suggested wear plates. I may also use it on the kitchen table for family entertainment.

However, I see no reason why you couldn't add legs. Another idea might be legs similar to an ironing board or electric piano/keyboard stand.

GregW66

Sound

Are you thinking the frame could be used as a speaker enclosure? This is an idea but I have a tiny bit of knowledge of speaker enclosures and the key is that the material be as solid and dense as possible. MDF or hardwood is best. The other issue would be tuning the box for optimal bass response. There are books and formulas dedicated to this topic. I used to also have a computer program from when I dabbled in car stereo installs but have lost that along the way. You would input the characteristics of the speaker (woofer) being used and a couple of dimensions and the software would spit out all the other dimensions including the proper size and location for a ventilation hole. 

"this project has no legs"

Looking at that photo of the module on the table top makes me think that modules the width of the table top could be a good plan. Divide the table length into half or maybe thirds then build more rectangular modules that can be tiled onto a string of table tops to whatever length is desired. Between operating sessions the tables could be folded up and stored and the modules stored on a rack or in a closet on shelves? Seems like 2 foot or whatever squares would be easier to build than longer modules and could be much thinner and still be stiff enough due to using the tables as a rigid base ?.....DaveB

tabletop modules

I think that could easily work, DaveB. The foamcore sheets available to me are 20"x30". I have many tables available to me at the church and I have free access to the hall. I could effectively build an entire layout this way.

GregW66

Trust your ears...

Dear Dr Geoff,

Like any exciter install, there is a metric boxcar load of variation in play, and the more accurate advice is to "trust your ears". (Even Parts-Express's own install notes say effectively the same thing).

That said, I've achieved 50 - 16kHz range from a pair of Dayton Audio DAEX25 exciters, mounted to the read of a "Brooklyn" style proscenium module, and around the same from a single DAEX25, powered directly from the output of a DreamPlayer Mini, underneath a 14" x 14" aussie winch foamcore display module...

With a suitable sound file and player/amp (DP + MilliAmp anyone?), it could certainly be used for layout sound...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Foamcore VS Humidity

Dear ???

I regularly use wet-on-dripping-wet scenery techniques with all-foamcore modules...
(that is literally pooled 50/50 water/PVA mix giving a white look to the ballast on "Toorong")

not a hint of warpage to be seen...
(and I have examples dating back over 15 years which are just as straight as the day they were assembled).

As for "ultra-thin" cross-sections, foamcore is functionally just like any other sheet material. To be strong in all 3 axis + longditudinal twist requires at least basic engineering principles to be applied, and appropriate levels of structural assembly. A 50mm/2" thick "domino" is well do-able, and capable of supporting most typical HO and even O scale trains...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Foamcore Speaker Enclosure? RE Exciters

Dear Greg,

No, the idea is to use Exciters, such as the potent DAEX25 exciters offered by Parts-Express.com, to turn the entire foamcore assembly into one dirty-great-big "speaker cone"...

http://www.parts-express.com/dayton-audio-daex25-sound-exciter-pair--300-375

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS Exciters make playing "find the speaker" soo much more fun....

"Toorong"s don't make a right

While gluing with the Weldbond which is essentially white glue but seems to have many of the properties of "Canopy Glue" some naturally squeezed out of the joints. I used a wet rag to clean these up. Aside from the usual problems with wet paper, I experienced no problems with warping. I thought, by its nature, the foamcore would be resistant to warping.

GregW66

You learn something new everyday

I did not know about exciters. What an interesting concept.

GregW66

My use of foamcore...

was a little different than this. I once built a 3x6 N scale version of the first Gorre and Daphetid plan. The actual baseboard was a 3x6 piece of blue foam but I cut all the subroadbed  out of foamcore.  I also cut the ramps to accomplish the grades out of foamcore. The whole thing was light and plenty strong.

Michael

Hot glue

I built a similar framework of foamcore and found it easy to work with. During a long move which included hot to cold to hot weather again in the pickup shell, I did have problems with warping.  The main problem,  though, was using Hot Glue ..... after this admittedly harsh storage, most of the hot glue joints failed completely. You would be advised to use something else if the layout is moved often.

Skip Luke

Holes

How does one make a hole in foamcore, can you drill it?

GregW66

Foamcore Holes

It is much easier to punch a hole through or cut it with a sharp X-acto knife. A small drill bit will easily go through it. The larger bits can sometimes tear through rather than cut through.

There are some wood drill bits like an auger bit that cut the circumference first, that might work for larger holes, but I've never tried them on foamcore.

When I do make a foamcore hole, it is always on top of a flat, wood, cutting surface.

'Hope this helps. Best Regards,

Geoff Bunza

Freemo 1/4Luan

Idea and planning great. Luan and freemo design lots better. No problems with wear and liquids. 

Must be something about Australia...

Dear Skip,

Must be something about the upside-down gravity down here, but hotglue has-been and continues as my go-to adhesive for all foamcore assemblies for over 20 years. (Lo-temp "arts and crafts" style hotglue, not the hardcore Construction-grade hotglue mind!).

The only time I've had a hotglue joint failure is when I consciously and deliberately applied significant force to split the joint...
(IE deliberately sheared a crossbrace T-joint from a module frame,
or reverse-flexed a corner L-joint to open-up and split the existign joint).

Many 1000s of kilometres of travelling, storage in conditions from warm-comfy domestic house thru to completely unlined and unsealed standalone steel shed/garage and unsealed boxtrailers,
in temps 0-45 deg C, and humidity 10-50%....

Happy Modelling,
Aim to Improve,
Prof Klyzlr