WILL COUNTY MODEL RAILROAD ASSOCIATION
MODULE STANDARD
INTRODUCTION
Welcome to the WCMRRA module layout standard document. This document is intended to help
members build layout modules which can easily be connected together, have them work reliably,
and get us to running trains as effectively as possible.
Don’t consider this document as a set of “rules” that are being imposed but as a set of good
guidelines that help ensure that we can get to having fun as quickly as possible and reliably have fun
as we continue to create module layouts. “Having fun” involves being able to connect modules built
by club members as well as other people outside the club following this standard so we focus on
running trains reliably without the frustration of worrying about how we’ll connect our modules
together or continuously messing around to get trains to run well. In that spirit, this document
describes both mechanical and electrical ways to bring these modules together in a variety of ways
resulting in the creation of a reliable and fun to operate layout. In order to reach these goals, we’ll
need to follow a few basic rules that will make our modules compatible with other modules in the
bigger world and we’ll also add a few “best practices” of our own as we learn about what works well
or what doesn’t work as well for our group. So hang in there and read through this document to get
an idea how we can best create modules that will work together to help us have fun.
Like building a club layout, we fully expect that some members will be more interested and more
comfortable in different aspects of the module construction; be it track work, wiring, scenery, or
even bench work. Keep in mind that we are a club and as a club, we can tap into and leverage the
skills of the different members in order to make the construction of your module less tedious and
more successful. So don’t hesitate to raise a flag if you want help in regards to some specific area of
your module; odds are we’ve got some that both loves to help in that area and is probably pretty
good at it.
This document often uses the term “we”. Consider this the “royal” we meaning all of us in the club.
While various members might have responsibility for setting up or hosting a particular session, it is
the responsibility of all of us to work together like we have in the past to make this a success so the
term “we” really should be taken as all of us working together.
Let’s work together and make modular railroading in the WCMRRA a success!
CREDITS
Let’s get this out of the way right at the start. We’re not doing this alone and we’re literally building
on the work of many others including:
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Modular Standard – March 23, 2015 Page 1
The Free-Mo Organization found at www.free-mo.org [FREE-MO].
The Minnesota Free-Mo Group found at www.mnfreemo.org [MNFREE-MO]
Northwest Trainmasters found at http://home.ix.netcom.com/~slyone/nwtm_new_home.html
[NWTM]
Sipping & Switching Society of N.C. found at http://gugliotta.home.mindspring.com [SS&S]
…and others as we learn about each other and interact in constructive ways.
Areas in the specification that are changed, been added, or are otherwise unique to us are denoted
by [WCMRRA].
Where applicable, this document will note the source of various information to both give credit
where credit is due and to help point you back to the original source of the information. For now,
we’ll use the above nomenclature (“[FREEMO] for example) to identify where various information
came from.
You may find some sections identified as “Editorial”; these are sections are added by the various
WCMRRA editors to help provide some background or other information that we felt might be
useful. No matter what bigger section these editorial comments are in, they are all our own
additions and hopefully don’t override the bigger specification or cause confusion; if you think they
do, please speak up and we’ll all work to get whatever topic clarified so we have less confusion.
LEGEND
[ S x.y, RP x.y, FAQ x.y, where x. and y are numbers - example: S2.15, FAQ1.7, RP
5.11 ]
S = Standard. All Free-mo modules and participants have to conform to the requirement/standard
stated so that we have better than a snowball’s chance in hell of getting our modules to connect and
operate correctly.
RP = Recommended Practice. These are procedures or specifications which are strongly
encouraged for maximal reliability or fidelity. Typically following these procedures will make some
aspect of module construction, connection, or operation easier, more reliable, or more durable so
I’ll strongly suggest that you give these a read and consider taking the advice given.
FAQ = Frequently Asked Question/Answers which explain the reasoning behind a particular
Standard or Recommended Practice. You can find some more information at
http://www.trainweb.org/freemoslo/Standards-&-Recommended-Practices-FAQs.html.
INTRODUCTION
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Modular Standard – March 23, 2015 Page 2
This section is from [FREE-MO] unless otherwise noted.
S1.1 The objective of the Free-mo Standard is to provide a platform for prototype modeling in a
flexible, modular environment. Free-mo modules not only provide track to operate realistic models,
but also emphasize realistic, plausible scenery; realistic, reliable track work; and operations. FreeMo was designed to and continues to push the envelope of modular model railroading to new
heights. It goes beyond the traditional NMRA closed-loop set-up in creating a truly universal "freeform" modular design that is operations oriented and heavily influenced by prototype railroading.
S1.2 Interoperability: The Free-mo Standard is a collection of requirements for building scale model
railroad modules that can work together with little effort, even when they have never been
assembled together before. The beauty of the Free-mo standard is that it allows builders to
replicate any freelance or prototype track plan within your modules boundaries, yet can be
combined for maximal interoperability with other Free-mo modules.
S1.3 A Free-mo module is a free-form module that conforms to the Free-mo Standard as outlined
below. (FAQ 1.5)
S1.3.1A Free-mo module can be any length and the endplates can be at any angle to each other.
Editorial: This is significantly different from the more rigid NMRA module standard where modules
need to straight, two foot multiple, etc. With Free-Mo, you can create a module that captures a scene
the way you want it to be. Want to create a sweeping 70 degree super elevated curve for taking
photos of your models? Go ahead; we’ll all work together figure out how to work that into a bigger
operating layout. Want to only build 3 ½ foot modules because that’s what fits in your car? That’s OK
too. Build what you like and what supports your interest. As a club, we might all chip in and build a
few “generic” modules like 90 degree corners or a turnaround loop or something like that but for the
main modules, focus on what captures your interest and we’ll all work together to take it from there.
S1.3.2A Free-mo module can be one physical section or a set of two or more sections that form a
module.
Editorial: This means that you can make a single larger “module” that might be split into more than
one “pieces” or “sections” and still be Free-Mo compatible. Think of it in terms of the “ends” of your
modules; you’ll want these to be Free-Mo compatible so you can fit into a larger setup but between
the pieces of your bigger module, you can build your entire “module” out of as many as many sub
modules as you think are appropriate with whatever configuration works for you.
Things that impact whether or how to “sectionalize” your module might be:
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Modular Standard – March 23, 2015 Page 3
1. Track work arrangements – you probably don’t want a section joint to slice right through the
most complex track work on your module.
2. Weight – if you keep it reasonable, your sections will bes easy to move and less likely to be
damaged or cause damage during that process (you need to at least get it down to the club,
right?)
3. Section size – can you actually transport your module? You’ll most likely need consider your
car, van, truck, or trailer
4. Material sizes – 4X8 is a relatively easy size of sheet goods so you are somewhat limited to a
single piece of no more than 8 feet. Depending on how you design your sections, some sizes or
shapes might make much more effective use of the material you buy; designing a module that
needs all 49” long pieces means you’ll probably end up with a lot of loss because you’ll need full
length sheets and end up not being able to potentially use close to 50% of your material.
Below you’ll find some photos of multi-part modules. Each module has one or more Free-Mo ends but
the connections between the sections are not Free-Mo and can only be connected one way but the
entire set of sections forms a single Free-Mo compliant module which can fit into any Free-Mo setup:
Brian’s 7 ½’ radius, super elevated, 90 degree corner is made of three distinct sections but forms one
big Free-Mo module. The Free-mo ends are shown with solid lines and the joints between the sections
are shown with dashed lines.
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This is Chris’ “branchline” module which goes from a Free-Mo double track to a single track going off
at a 30 degree angle. It has two Free-Mo double track ends and one Free-Mo single track end. It is
essentially a rectangular section plus a triangular section as shown by the dotted line between them.
This is Chris’ “T” module designed to connect to the yard. The longest section is 9’ long and 26” wide
with a second section which is about 42” wide where it connects to the other module and about 35”
deep. The primary reason for making this module in two sections is to keep the sizes of the pieces
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Modular Standard – March 23, 2015 Page 5
more manageable while still accommodating 42” radius curves coming into the yard from the double
track mainline.
One thing to keep in mind is that if you are building a bigger scene (a scene that might extend across
more than one physical module, you might still want to consider building each section as a Free-Mo
module if it doesn’t limit you too much. If you do it that way, your bigger scene could be rearranged
and connected differently at different times for more variety in the future.
S1.4 The Free-mo Standard governs the ends of the module and basic track requirements. Most
Free-mo modules have two ends, but modules can have one, two, three, or more ends. (FAQ 1.1)
S1.5 Free-mo modules fall into three basic categories:
S1.5.1 Mainline - Mainline modules represent Mainline rights-of-way. Mainline modules are
designed with large radius curves and minimal grades.
S1.5.2 Branchline - Branchline modules represent Branchline rights-of-way. Branchline modules
can have smaller radius curves and steeper grades than Mainline modules.
S1.5.3 Mini-mo - Mini-modules (mini-mos) have end plates that are narrower than the standard
width endplate. With this in mind, a mini-mo can be Mainline or Branchline module, single-track or
double-track. (S1.6)
S1.6 Mini-mo type modules are intended to be a Free-mo subset and not replace or exclude an
equivalent length standard module. Full width modules are generally more stable and should be
used wherever possible.
Editorial: If you’re planning on making a very narrow module, keep in mind how mechanically stable
it would be when connected to other modules; wider modules tend to “sit” better and connect better so
don’t make your module excessively narrow unless it really fits your module’s goals. Also keep in mind
that the Free-Mo standard requires that tracks be at least 4” from the module sides which means even
the skinniest of single track mini-modules would still be about 9” or so wide.
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2.0 FRAME AND LEGS
S2.1 End plates shall be 3/4" plywood or equivalent (birch plywood works well) to provide
sufficient strength for clamping to adjacent modules. (FAQ 2.1, RP2.1.1)
RP2.1.1 Avoid Dimensional Pine Lumber for your frame work. It has a tendency to warp and "cup"
with age, throwing off track alignment. It has also been found that plywood (birch plywood works
well) warps and twists less than dimension lumber (3/4 inch pine boards). (FAQ 2.1)
Editorial: At first this seems like a pain in the ass when lumberyards are full of standard dimensional
lumber (2X2s over here, 1X6s over there, etc.) but it is an important part of creating a module that
works well and stays working well. Think of how hard it is to find a straight piece of dimensional
lumber in the lumberyard in the first place; you can go through a dozen pieces to find a piece that is
both straight and twist free. If you’ve done much with wood, you’ll know that even when starting with
a “straight” piece, they don’t always stay straight; the problem is that ordinary dimensional lumber is
“literally” grown (it was a tree you know) and the tree grew the way it wanted to grow and had no
idea it was going to become part of your module in 10 years.
“Engineered” wood like plywood for example is intended to alleviate some of these problems by
laminating the wood together in a way that it becomes more structurally stable both to start with and
it tends to stay that way down the road (though if you’ve ever spent time in lumberyards, you’ll find
some real “interestingly” shaped pieces of supposedly engineered pieces of wood as well; speaking
personally, when I see those, I just move them out of the way and look for something better). Given
some of the specific sections of our own traveling layout that while constructed well using exteriorgrade wood, still seem to incorporate “cursed” pieces of wood that always need cajoling, twisting, and
serious bolt tightening action to pull together, it’s probably worth it to start with some of the best
wood you can get in the first place and not cut corners here. Unless doing and redoing bench work is
the thing that really gets you pumped up, you probably want to do the bench work for your module
once and move on to the more interesting parts. That means starting with a good base seems to make
a lot of sense. A good club effort would be for several people to join together to buy some sheets of
better grade suitable plywood (like 13-ply ¾” birch) and rip them into strips for people to use in
building their modules and make it easier on everyone.
S2.2 Single-track endplates shall be 24 inches wide by 6 inches tall.
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S2.3 Double-track endplates shall be 26 inches wide by 6 inches tall.
S2.4 Roadbed shall be 1/4 inch cork or equivalent on 1/2 inch plywood or equivalent. Foam tops
are acceptable if braced to prevent sagging or flexing.
Editorial: The real key is that if your roadbed is at the right height, your track will be at the right
height. Keep in mind that it’s your module so your responsible for building something that won’t sag,
flex, or otherwise ruin the run so build something that will hold together so you can spend your time
running trains and not messing around with your module.
S2.5 The nominal and minimum height of the rail head, at the end plate, is 40 inches from the floor.
(WCMRRA, FAQ 2.2, FAQ 2.6)
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Editorial: The Free-Mo standard calls for a rail head height of 50” from the floor; 50” is high,
probably too high for our club as we want to be able to accommodate all members well. We've made a
lower height standard to be more accommodating. NWTM use a rail head height of 40” from the floor
but members generally keep different heights in mind by making their legs changeable. MNFREE-MO
seems to stick with the 50” rail head height. Since the NWTM folks are local and I could see us
working with them quite a bit as modules get developed, we are specifying a rail head height of 40” for
compatibility with them and ease of access for all interested club members.
Again, if you make your legs changeable, your module should be able to work in a variety of situations
with nothing more complicated than a different length set of legs.
S2.6 On modules with grades, the elevation of the high end shall be some multiple of 3/4 inch above
low end.
Editorial: Using this ¾ multiple standard means that if you module has a grade and connects to
other “flat” modules, these modules could be connected to the “high side” of your module and
nominally raised with “spacers” made from ordinary 1X “planks” to bring those modules level with the
raised end of your module. How many and whether we’ll even need to whip up these sort of spacers is
a bridge we’ll cross when we get to it but if you want to make a “grade” module, it wouldn’t be a bad
idea for you to bring along a fair number of spacers to raise up other modules up since your sort of
causing this situation in the first place.
Also keep in mind the fact that the grade is limited to 2% so your module needs to include enough
length to have at least 6” of straight and level track at each end, a “vertical easement” to smoothly
transition in and out of the grade, and then the grade itself. Considering this, it takes most of
significant length module to raise up only ¾ of an inch:

12” straight and level track (6” at each end)

24” of grade (2% grade is about ¼” per foot so it would take 2’ to make a ½” grade change

24” of vertical easement (figure 12” on each end with about a 1/8” grade change eased over
12” total; combine the easements with the grade section and the total comes out to be about
¾” total grade change)
This puts the length of a minimal grade change module at 5’ using the maximum grade permitted. It’s
not clear how many people are actually building “graded” modules since it seems to put a significant
burden on the rest of the layout to accommodate just a single graded module so my recommendation
is to stick with “flat” modules, at least in the early stages, for maximum flexibility.
S2.7 The maximum height of rail head, at the end plate, is 52 inches from the floor. (WCMRRA)
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Modular Standard – March 23, 2015 Page 9
Editorial: The Free-Mo standard calls for a maximum height of 62” (50” specified height plus 12”);
I’ve adjusted our specification to be 12” above our 40” recommended height.
If you want a module this high, you better think about how you’re going to connect to the rest of the
40 or 50” world!
S2.8 The module (set) shall have at least four legs and stand on its own.
Editorial: This is important because unlike our traveling layout which connects in a very specific way
and can “share” legs between modules, there is no telling how, to what, or in what direction your
module might be incorporated into a larger setup. By having your module completely “stand alone”
(literally), we can connect modules any way we like without worrying about support issues.
You can find some interesting latching leg brackets at Lee Valley Hardware. They are surface
mountable and allow for easy attachment of legs up to 1 ½” in width (basically a 2 X 2). They lock in
both a closed and open position making setup and transportation easy.
You could also make a “pocket” in the corner of your module similar to how the travelling layout legs
are attached which would make moving the module easy (since you just pull out the legs) and would
make accommodating different layout heights very easy by just replacing the entire leg.
There are a number of ways to create sturdy, easily removable or collapsible legs; below are some
pictures of a tool-less, low cost strategy for removable legs:
If you make the pockets “tight”, these are very sturdy but I am still considering adding a method of
using a screw per leg to firmly secure the leg to the module as the fit has to be “tight” but not so tight
as to make it difficult to insert and remove the legs. Even a little bit of “slop” to just make the leg
insertable in the pocket becomes a lot of movement at the end of a 40 or 50” long leg so some means of
mechanically securing the leg would be good; an added benefit is that you can lift and move a “legged”
module if the legs are secured without the risk of having a bunch of legs dropping out of their
mounting pockets.
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Other alternatives deployed in already built modules include PVC legs (take a look at Brian’s large
radius corner module set for an example). A few photos are show below:
There is nothing saying that you can’t come up with some blend of these two or something totally
new. Think of how reliable, strong, and easy to build your ideas might be and you’ll probably go off in
a reasonable direction. Keep in mind that a lot of stability comes from the modules being clamped
together so your individual module doesn’t have to be massively over engineered to stand like the Rock
of Gibraltar on its own and can gain stability from being bolted to other modules but also don’t forget
you’ll be building your module standing alone so you’ll need something reasonable. If you can work on
your module standing alone, it’s probably plenty stable enough to fit into larger setup and not be the
weak link.
S2.9 Legs shall have continuous adjustment of plus or minus 1 inch (screw type foot).
Editorial: The easiest way to do this is with screw-adjustable leveling feet and a T-nut at the bottom
of each leg. If you want a lot of adjustability, check out these leveling feet with 4” of adjustability from
Lee Valley Hardware.
S2.10 The bottoms of the legs shall have rubber tip or equivalent floor protection.
Editorial: Consider we’ll potentially be setting up on anything from concrete floors, to asphalt
driveways, to finished gymnasium floors and we don’t want to damage the floors if we want a chance
at ever getting invited back.
S2.11 Modules may be used with operators and spectators on either or both sides. (FAQ 2.3)
Editorial: No telling how your module might go into a specific setup so it makes sense to allow it to
be connected either way and for both sides to not only look “nice” but also provide a means to actuate
turnouts and other modules features as needed from either side.
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S2.12 There are no special bench work construction requirements for Mainline Modules in excess of
the standards specified above (S2.1 through S2.11).
3.0 TRACK
S3.1 Modules shall use Flex or hand-laid track.
S3.2 The center line of the all tracks shall be 4 inches or more from the sides of the module at all
times. (FAQ 3.1)
S3.3 On a Single-track module, the through track shall be centered on the 24-inch end plate. (FAQ
3.4)
S3.4 On Double-track modules, the two through track center lines shall be spaced precisely 2 inches
apart and centered on the 26-inch end plate. (FAQ 3.5)
S3.5 Track on the through route must be perpendicular to the end plate for 6 inches from each end
of the module.
S3.6 Track on the through route must be straight and level for 6 inches from each end of the
module.
RP3.6.1 The points of a turn out should not be within 6" of the end of a module.
S3.7 Rail shall be cut off 1 inch away from module end; ties and ballast shall be continued to the
module end for good appearance and matching with the adjacent module. Ties shall be notched
under the ends of the rails and to the module end, to clear bridge rail joiners and provide freedom
of adjustment for bridge rails. (FAQ 3.2)
Editorial: Here is an example; note the notched ties for clearance for the rails and the use of the
notched ties far enough back to support the installation of a regular or insulated joiner:
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Modular Standard – March 23, 2015 Page 12
RP3.7.1 To enable DCC power districts, your module must be able to accommodate insulated rail
joiners at each Free-mo end plate.
RP3.7.2 Free-mo printed circuit board tie plates are recommended for ends. (F7.1)
RP3.7.3 Tie plates where the fitter rails go over should be excavated slightly to permit fitter rails to
accommodate any vertical irregularity in track alignment between adjacent modules.
Editorial: An example of the notches described above can be seen in the preceding photo.
S3.8 Turnouts shall be at least #6.
Editorial: #4 turnouts are a little too tight for medium and larger steam engines and 6 axles diesels
so for maximum flexibility, stick with larger turnouts and avoid the excessively sharp turnouts – if you
can fit a #8, consider going that route; your trains will thank you..
RP3.8.1 Turnouts on the module through route should be #8 or larger.
Editorial: Consider that the mainline should be able to support the operation of 80’+ full length
passenger and freight cars, keeping the mainline turnout on the larger side helps a great deal. If you
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are coming off of the mainline for an industry or some situation that doesn’t support or make sense for
this sort of rolling stock (no one is spotting a heavyweight passenger car at a coal tipple for example),
a #6 turnout off of the mainline might make sense for your module.
S3.9 There shall be a minimum of 12 inches of straight track between reverse curves.
S3.10 Track on the through route of a Mainline module must ALL be Code 83 nickel-silver rail
without exception.
S3.11 Sidings, spurs and other tracks of a Mainline Module may be Code 83 or smaller, but shall be
no less than Code 40.
S3.12 The Minimum permitted curve radius on a through route of a Mainline Module is 42 inches.
This includes through track sidings and other tracks where through traffic will run. (RP 7.4)
RP3.12.1 While the minimum permitted radius of curves on the through route of a Mainline module
is 42 inches, 48 inch and larger curves are preferred.
RP3.12.2 Transition curves or easements are strongly recommended to ease long cars in and out of
curves. [WCMRRA]
Editorial: I know most of us probably started with 18” radius snap track but the larger radius, the
better. MNFREE-MO recommends a minimum mainline radius of 48” and branch line minimum of 36”.
I would strongly recommend this sort of radii. Right now, we have the situation where the largest
radius curves on the traveling layout (which I think are about 30”), are not sufficient to run 85’
passenger cars or some long wheelbase steam locomotives without problems (“problems” meaning
they flat out derail and can’t be run reliably so as not to understate the issue). We want to be able to
accommodate the full range of locomotive and rolling stock possibilities so we are aiming for broad
curves here.
Easements leading into and out of curves makes a very significant difference and become even more
important if you are working at the minimum radius. Strongly consider using curve easements. You
can find some good information and examples on layout and using easements at:

El Dorado Software (makes of the PlanIt! software package)

A description of how to calculate and print easements
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
A great article on curves from Model Railroad Hobbyist (a very good online only model
railroading-oriented "magazine") that will really make you think about curve radius.
S3.13 Spacing between tracks on curves of a Mainline Module shall allow for long cars to operate
without fouling each other; observe NMRA Standards S-8 Track Centers for "Class Ia" equipment.
Editorial: We want to be able to not just operate long locomotives and cars on our modules but we
want to be able to operate them passing each other on a curve without side swiping each other.
Here are some standards recommended by the NMRA:
Class II
Includes small four-wheel truck diesels, geared and other small steam locomotives
with short end overhangs typical of old-time, logging and branch lines and equivalent
rolling stock.
Class I
Includes longer steam locomotives typically with two-wheel trailing trucks, larger four
and six-wheel truck diesels and equivalent rolling stock.
Class Ia
Includes the largest steam locomotives with four-wheel trailing trucks, articulated
locomotives, those with rigid wheelbases in excess of 20 feet, full length passenger cars
and other long rolling stock.
RadiusInches
Class II
Class I
Class Ia
53
40
32
1 7/8 1 15/16
2
2
2 1/16
2 1/8
2 1/4
2 3/8
2 1/2
Considering we’ll want to keep the option to run full size locomotives and rolling stock through these
modules, please use the Class Ia clearances as appropriate for the radius in use – remember, when in
doubt, go a little wider in spacing.
While Free-mo specifies 2” separation between double track mainlines at the module ends (and
implicitly across the length of the module if the mainline is just straight), you can and should open up
the spacing on the curves. The easiest way to do this is to start the “inside” track curving a little
earlier and the “outside” track curving a little later. This will give you the extra spacing you need. To
double check your spacing, you can easily measure from one right rail to the other right rail (or left
rail to left rail); that way you won’t have to worry about estimating your measurements from between
two sets of rails.
S3.14 Mainline maximum permitted grade on the through route of a Mainline module is 2.0 percent
(approximately 1/4 inch per foot). (FAQ 3.6)
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S3.15 Vertical curves on the through route of a Mainline module shall be appropriate for Mainline
operation of contemporary long cars, see Standard S-7 Clearances and the NMRA Gage, and NMRA
Recommended Practices RP-11 Curvature and Rolling Stock.
4.0 WIRING
Editorial: Full tilt modular layouts basically require DCC. Since the layout is “temporary” in some
aspects, there will never be a single “control panel” to control turnouts from and there is no notion of
“blocks”. The modular concept is based on you following your train across the modules and using local
controls for things like turnouts which are mounted on the module you are operating on.
While any DCC system is the same once a locomotive is on the track, throttles and many other
components are a different matter. Brand X throttles will only work with Brand X command stations.
To help clarify, the figure below shows the basic components of a DCC systems (figure from
http://www.awrr.com/dccintro1.html):
While the decoders in the locomotive can be from any manufacturer, and the DCC control systems (as
shown by the Command Station, Cab(s), and Booster) can be from another, the entire DCC control
system is typically from a single vendor.
The Free-Mo specification specifies the use of a 6-conductor connection for the cab bus and refers to it
as “LocoNet’ wiring. LocoNet is a Digitrax-specific term used to refer to the wiring for the cabs and
other accessories that don’t connect to the track. In this way, the free-Mo standard implies the use of
the Digitrax system. This doesn’t mean that only Digitrax will work on a Free-Mo system as this 6
conductor wiring is actually the same sort of wiring used by the NCE DCC systems (in fact, NWTM use
NCE as their DCC system for control of their modules); I believe the Lenz DCC system also uses this
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same sort of wiring. Unfortunately, most other vendors use their own wiring standard but the FreeMO wiring standard works for the two major systems in use: NCE and Digitrax.
WCMRRA is moving to NCE but modules constructed to the Free-Mo standard will work with either
NCE or Digitrax because they use the same cab wiring – however, any NCE cab won’t work on a
Digitrax system and vice-versa. If you take your module to a Free-Mo meet and they are strictly
following the standard, you can get a Digitrax cab to actually operate a train but your module will
work fine and meet all of the applicable standards.
S4.1 Wiring consists of 2 pairs of bus wires (track bus and accessory bus) and a 6-conductor
module phone type cab bus cable.
Editorial: This type of wiring is suitable for both NCE and Digitrax configurations.
S4.2 Track and accessory bus wire shall be 18 AWG stranded or larger.
RP4.2.1 It is recommended to use 14 AWG stranded wire for the Track and Accessory Bus. Even
better is 12 or even 10 AWG Stranded wire.
Editorial: DCC uses a lot fewer wires but the wires that are used are more important in regards to
being sized correctly because more of the layout’s trains are using these fewer wires. This is a case
where bigger is better – the larger the wire, the less problems we’ll have with voltage drops as layouts
get bigger. It would be best if people used the larger wire from the get go to allow modules to work
together as well as practical.
S4.3 The cab bus shall be telephone type 6-conductor cable.
S4.4 There shall be a 4 (or more) position barrier strip under the module at each end for track and
accessory bus wire hook-up.
Editorial: A typical example is shown below – this basically provides a strain relief for the wiring on
the module – any yanking would yank the wire loose from the barrier strip and not from the rest of the
module – cost is typically under $2 each – a module would need one of these at each end.
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Modular Standard – March 23, 2015 Page 17
S4.5 All ends shall have a pair of 2-pin Jones plugs, one male and one female (Cinch Part Number P302-CCT and S-302-CCT or equivalent) for the track bus. (FAQ 4.1).
Editorial: These are available from a number of vendors as shown below:
Vendor
Jameco Electronics
Mouser
Allied Electric
Demar Electronics
Male Plug
248760
538-P-302H-CCTL
750-3200
P-302-CCT
Female Plug
248807
538-S-302H-CCT
750-3201
S302-CCT
The connector being described is shown below – these run about $3-4 each – a module needs 2 at each
“end”.
S4.6 All ends shall have a single, 2-pin trailer plug (Radio Shack Part Number 270-026 or
equivalent) for the accessory power.
Editorial: The connector being described is shown below – these run about $6 a pair at Radio Shack;
likely we can find them much cheaper than that – each module needs one pair (one at each end).
Polarity is identified by the wire colors molded into the connector – maintain polarity across your
module by matching colors at each end.
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These are available from a number of vendors including those shown below; this connector is actually
made by Hopkins Manufacturing and is their part number 47965:
Vendor
Radio Shack
AutoZone
Race Mart Superstore
American Science and Surplus
Part Number
248760 (about $6)
47965 (about $3)
HOP-47965 (about $1.50)
39379 ($2.95 for a pair,
sometimes on sale for less)
These connectors are sold in a “loop” where they are basically on a 12” or so long wire loop and
typically are cut apart and used individually. You’ll probably find that the remaining length when
they are cut apart is quite short so before installing them on your module, you’ll want to “extend” the
leads by splicing extra wire length on them; you could use crimp connectors or solder and tape or heat
shrink tubing but I would recommend not using something like wire nuts (please!).
S4.7 All ends shall have a surface mount "6 conductor 6 position" module jack (RJ12) mounted to
the inside of the end plate for the DCC cab bus. .
Editorial: There a couple of ways to handle this; you can use a “single position” jack assembly which
means you need to wire the rest of the cab bus off of this end jack assembly or you could use a dual
jack and use ordinary 6 conductor RJ12 patch cables to connect from one end to the other (and
connecting to the throttle connection plates as shown in S4.12). Since the throttle connection plates
have RJ12 connections on the back of them for the cab bus, it might be easier to just make up proper
length patch cables for all cab bus connections.
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Below are some examples of single position jack assemblies:
As an alternative, below are some dual, or two position jack assemblies. Most of these already
connected the two jacks together so all you need to do is mount them and they are ready to use (note
that if you use a “flush” style plate, you’ll need to provide some sort of bracket or box to mount it on or
in)
Below are some examples of dual position jack assemblies:
The most cost effective solution available locally seems be at Menard’s using a Philips SDJ6110W/17
surface mount jack. The run about $1.50 each and are smaller than most of the jacks typically seen
(only about 1¼” X 2” in size so they are almost ½ the size of the typical jacks which makes it easier to
mount on your module frame). To make it easier to find these in the event you go looking for them, a
picture of a packaged and an opened jack is shown below:
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S4.8 Through route wiring is as follows for Jones plugs (you should be facing module end for
correct perspective): (FAQ 4.2)
S4.8.1 Track Connections – Single-track modules
Male contact 2 right rail (large pin)
Male contact 1 left rail (small pin)
Female contact 2 left rail (large socket)
Female contact 1 right rail (small socket)
Editorial: The Contact “1” and “2” designation is shown on the plug itself under the cover. Note that
standard Free-Mo modules have two sets of connectors wired the same way and wired together
(electrically speaking, they are “in parallel”): one set male and the other female. This allows modules
to be “flipped” end for end and still make the necessary electrical connections. In a normal single
track Free-Mo connection, only one set, male or female, is needed at any one time; the other can just
be left unconnected (though connecting it is benign and hurts nothing). Having a hook or something
to “hang” the unused connector or to keep them out of the way when transporting your module would
be a nice touch for a clean look.
S4.8.2 Track Connections – Double-track modules
Male contact 1 left rails (large pin)
Male contact 2 right rails (small pin)
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Female contact 1 right rails (large socket).
Female contact 2 left rails (small socket)
Editorial: Note that in a double track configuration, both right rails are tied together and both left
rails are tied together. The Contact “1” and “2” designation is shown on the plug itself under the cover.
Below is a diagram showing an easy way to confirm the wiring of your plugs:
You can use an ohm meter to easily check out your wiring by testing the continuity from the plugs on
each end to the rails – if you can successfully verify the connections, you’ll be most of the way to
getting things compatible with other modules.
RP4.8.1 - On double track modules, to facilitate optional train signaling/detection, separate feeders
are recommended for each track so that detection can discern a train on track A or track B.
Editorial: The easiest way to do this is to wire each track to a separate connector as described above
and not connect the tracks to each other – this will make it possible for modules to support train
detection on each track individually in the future if this becomes common.
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RP4.8.2 To ensure strain-free electrical connections between modules, all fixed wiring such as the
track and accessory bus connections should extend 12” past the end of the module frame for ease of
connection to other modules. [WCMRRA]
S4.9 Track feeder wire must be 24 AWG or larger, but not longer than six inches to the track bus to
avoid voltage loss.
Editorial: These are the drops from the track to the heavier gauge power bus under the module –
more is better – consider using one drop per track section and relieve the joiners from having to carry
power from track section to section.
S4.10 All turnout frogs shall be powered. Turnouts shall not rely on switch points to power the frog.
Editorial: Yes, a lot of equipment will run fine over dead frogs but the better the electrical feed to you
locomotive, the better the operation; smoother, more consistent, and if you are using sound, no sound
interruptions. The standard says frogs should be powered and while we could potentially let this slide
in our own operations, when you show up at a bigger Free-mo event, the coordinating folks might
insist on this and not let your module participate and since it is part of the standard, they would really
be right. If you have your frogs powered from the get-go, you’ll be ready for pretty much anything and
everyone’s equipment will run as well as it can.
S4.11 Accessory power shall be approximately 16 volts AC or DCC. The bus is wired straight
through. A bridge rectifier and filtering capacitor may be used to convert AC or DCC signal to DC.
Applications that require AC or DCC signal may utilize power directly from the bus. (FAQ 4.3)
Editorial: Be careful; note that the accessory bus could be either AC or DCC (which is just a special
form of AC). Guess which one is probably the most common; I would bet AC rather than DCC. This
means you cannot count on being able to operate things on your module under DCC control and need
to provide a way to operate things if DCC is not present on the accessory bus.
S4.12 Each module will have one dual flush mount "6 conductor 6 position" modular jack (RJ12)
faceplate mounted on each exposed side of module, for throttles. (NCE UTP Panel, or equivalent like
the “universal” UTP panel (works with Digitrax, NCE, and several others) from Tony’s Trains)
In order to accommodate both NCE and Digitrax use, use only NCE-compatible fascia plates.
NCE-compatible plates will work for both NCE and Digitrax systems while Digitrax plates do not
connect all of the wiring needed for NCE compatibility. In particular, the Digitrax UP-5 Throttle
Jack will not work with NCE systems even though it has the same jack so please do not use it on
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your modules to maintain NCE compatibility. The plates mentioned in the preceding paragraph
will all work and should be the ones used in Will County Modules. [WCMRRA]
Editorial: Some typical panels are shown below – these provide a place to plug in your DCC throttle
for walk around operation – the same panel and associated wiring works for both Digitrax and NCE
DCC systems since they are wired the same way if you use NCE-compatible throttle connection
plates.
The “front” or fascia side of the plate has two connections to plug in your DCC throttle while the rear
has two more connections to plug into the cab bus. Usually these types of plates are “daisy-chained’
together on the back side with jumper cables going from one to the next.
Both NCE and Digitrax use the same style plates and wiring so modules with this sort of plate will
work for either system (the Tony’s Trains plate mentioned above and shown in the right photo is sold
as a “universal” throttle jack for both of these systems – it actually seems to be a NCE plate with a
repainted plate and a sticker on the outside).
You could also alternatively use a regular 6-conductor flush phone jack and wire to the screws on the
back. You only need one throttle connection so this is completely within “spec”.
NCE also offers what is considered a more “rugged” throttle connection plate using a 5-pin “DIN”
connector as an alternative to the telephone RJ12-style connector; this requires a special throttle cable
with a DIN on one end and an RJ12 on the other since the NCE throttles use an RJ12 on the throttle end
of the cable. This is the style used by the Northwest Trainmasters; if we want to do joint operating
sessions with them, we’ll need to address this some way. It’s easy to “patch in” extra RJ12 panels by
just using a few extra RJ12 cables and connecting on the back side and you can add a DIN-style panel
in the same way; if we end up inter-operating, it might not be a bad thing for each group to bring a
few extra panels to temporarily mount along the setup to make it easy to plug in their style of throttle
cables.
An example of the NCE DIN-style fascia panels is shown below:
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Note that even though it uses the round DIN style connection on the fascia (throttle side), it uses the
same RJ12 connectors on the back side so it would be easy to patch a few of these into an Free-Mo
setup just by replacing the RJ12-style panels with a DIN-style panel.
RP4.12.1 For maximal convenience in areas where operators congregate (such as yard modules)
one or more modules in these areas should have more than one set of throttle jacks per side.
RP4.12.2 On Multi-Section Module, each module sections should have a dual flush mount "6
conductor 6 position" modular jack (RJ12) faceplate mounted on each exposed side.
Editorial: Regarding the above recommended practices, this isn’t a new type of connector or panel,
it’s the same panel as specified in S4.12; just a recommendation that help make it easier for multiple
throttles to be connected where operators would naturally congregate (like yards) or across larger
modules. This is a recommended practice and not mandatory; my feeling is that if your module
doesn’t include switching, one throttle connection is enough. Consider Brian’s three piece curve, one
throttle plate is fine since I don’t see people needing to plug into three different places to negotiate a
curve; when you need to plug in again, you’d just hop to the next module and plug in there.
S4.13 All of the cab bus connectors and associated cables need to be connected together straight
through (i.e. pin 1 - pin 1, pin 2 - pin 2, pin 3 - pin 3, etc. ...note standard telephone cables are NOT
wired straight through).
Editorial: These cables are easy and cheap to make by buying a roll of the 6 conductor flat cables,
ends, and a crimper – you’ll need these for making the connections between the ends of your modules
and the pluggable throttle face plates on the sides of your module as well as having short jumpers
between modules.
Be sure to get the 6 conductor wire and the matching 6 conductor ends. There are also 4 conductor
versions available; in telephone terms, these cables are typically referred to as “multiline or 3 line”
cables and connectors and you might see the 4 conductor accessories referred to as “2 line”
accessories. The 6 conductor connectors are referred to as “RJ12” connectors which their 4 conductor
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relatives are commonly referred to as “RJ11” – make sure you are using RJ12 connectors and the
corresponding 6 conductor cable.
Note that “straight through” means that if you put the connectors next to each other in the same
orientation, the colors in the cable read the same left to right on each connector (the connectors are
clear so you can see the individual wires – the “straight through” aspect means that pin 1 on one
connector is connected to pin 1 on the other, and so on). The exact order of the colors is not
important, just the fact that the colors are in the same order on each connector. As mentioned above,
telephone cables are not wired this way, the color order in each connector will be reversed from one
connector to another. Another way to tell a “straight through” cable is to pull it tight and keep the
cable flat; a “straight through” connector will have the connectors “flipped” from one end to the other
(meaning the connectors will be reversed, the connector clip will be on one side at one end and on the
other side on the other end) while a telephone style connector will have both connectors in the same
orientation (you’ll see this as having the clip part of the connector on the same side of the cable on
both ends).
See the diagram below for a “straight through” cable wiring example; note how the connectors on
each end are “flipped” with regards to one another:
Crimpers run about $25, wire is about 25 cents per foot in bulk, and the crimpable ends are about $3
for a dozen. A typical module will need a 24” patch cable plus two connectors, enough wire to go from
each end to each other end plus a couple of feet extra and ends for each of those cables as well. A
typical crimping setup is show below (this one is from Lowe’s and runs about $25; Menard’s, Home
Depot, Ace, etc. will all also have these for about the same price).
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Don’t try to skimp here and get one of the plastic-bodied crimpers; they really don’t last in the long
term and actually work pretty poorly in the short term.
In reality, you really don’t even have to buy the tool; I’m sure that someone in the club has some and if
you ask nicely and offer a beer or two, they probably will not only let you use it, but probably even help
you do it.
S4.14 To connect the cab busses between modules, a 2-foot RJ12 to RJ12 type straight through
cable is utilized.
Editorial: This means each module should be brought out with a cable to make this connection; don’t
count on the fact that someone brought a spare or two and make this part of your module accessories
you’ll bring along to an operating session (if you want to get good karma points, you could be the
person who potentially saves the day by bringing an extra cable or two for this purpose).
S4.15 To connect a DCC booster to a module, There are two connections that have to be made. (1)
The cab bus (2) The Track Power.
S4.1.15.1 For the cab bus, a 4 foot RJ12 to RJ12 type straight through cable is utilized.
S4.1.15.2 For the Track Power, a 4 foot cable with one female and one male 2 pin Jones plug on one
end is used. It is plugged between interfacing modules and connected to the output of the booster.
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5.0 CONTROL
S5.1 LocoNet compliant DCC and accessories are standard for interoperability within and between
Free-mo groups. For more information about LocoNet Technical specifications consult the Digitrax
website.
S5.2 For a given turnout, turnout controls must be on all sides of the module or module section,
excepting any end plates.
Editorial: Ground throws are an acceptable way to control turnout but keep in mind how you’ll
power the frog of any such controlled turnouts.
RP5.2.1 Turnout controls should be located on the fascia, and not on the horizontal or vertical
surfaces of your scenery.
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RP5.2.2 Ground throws are an acceptable way to control non-mainline turnouts. Frog power
switching is still required so the use of something like the Caboose Industries power routing ground
throws is strongly recommended. [WCMRRA]
FAQ5.2.3 DCC turnout control – while you could use DCC decoders to control turnouts on your
module, we require local control and you may wish to consider some sort of a quick-disconnect to
disconnect your turnout decoder from the DCC accessory bus to prevent unintended operation.
The source of the problem is that if a number of people start using DCC-controlled accessories like
turnouts, we will need to manage the addresses of these devices to prevent unintended device
actuation (like having two turnouts respond to the same accessory decoder address possibly
throwing a turnout right under an operating train for example). The easiest solution for reliable
operation is to use only local turnout control and not to use DCC for this situation. [WCMRRA]
Editorial: Note that the requirement for local turnout control could be met using electrical (think
switches and Tortoise switch machines for example) or mechanical means (rods and knobs for
example). Either way would work but you may want to give consideration to a control mechanism
that would be flush or recessed enough so that the side of your module doesn’t have any controls
sticking out past the side of the fascia; this makes your module more durable and makes handling or
moving the module less likely damage your control mechanism.
You will also need to think about how you will power the switch frogs using whatever turnout control
mechanism you choose.
6.0 SCENERY
S6.1 All bench work shall be hidden by some form of scenery.
Editorial: Since we’ll be starting out, we’re going to have a number of modules “under development”
for some time (maybe forever as people build new modules) we don’t have to require modules to be
fully sceniced in order to be acceptable but we should strongly encourage people to keep making
progress on their module as time goes on because it rises the level of enjoyment for all participating.
We would hope that as we get together over time, a module will progress towards completion in some
sort of measurable way – having the same module turn up as bare foam time and time again sort of
ruins the illusion we’re trying to achieve.
S6.2 General module fascia color shall be Glidden 70GY 08/075, "Northwest Green" in an eggshell
or semi-gloss finish or an equivalent color. [WCMRRA]
Editorial: We can agree on some nice neutral fascia color like the MN Free-Mo folks did; in fact, they
agreed on ‘Glidden 70GY 08/075, "Northwest Green" in an eggshell or semi-gloss finish’. I believe the
NWTM folks use a similar color if not the same. It looks good so why argue about fascia color and if
we get a quart or even a gallon, that’s enough to do a lot of module fascias. In the Will County area,
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Glidden paints are carried by Home Depot but I was able to get a quart at my local Ace Hardware in a
Benjamin Moore blend; most paint stores can look up this color formula using the manufacturer and
color name so you aren’t limited to having to find “Glidden” brand paint to finish your module.
One tip, paint only the externally visible parts of your fascia and leave the ends that connect to other
modules “au natural”; latex paints tend not to ever really “dry” hard like oil paints of yesteryear and
clamping two latex painted end plates together will basically press the two painted surfaces together
so hard that the paint will fuse in some places and will lift off one of the modules when they are taken
apart making them not just hard to separate but harming the ends and leaving uneven blobs of fused
paint. Yuck.
S6.3 Scenery at the Free-mo standard end(s) shall have a flat profile 3/8" below the top of the rail
on the through route.
S6.4 The through route shall be ballasted with a 50-50 mix of Woodland Scenic's "Light Gray, Fine
#785-74" and "Gray, Fine #785-75" or Woodland Scenic's Gray Blend, Fine or equivalent,
[WCMRRA]
S6.5 Standard rail color on the through route is Floquil/Polly-S Roof Brown or equivalent.
RP6.5.1 Ballast on Through route is to be weathered with a fine mist of thinned Floquil/Polly-S
grimy black or equivalent.
Editorial: These are intended to make things look consistent from module to module so people don’t
tend to see “modules” but see a larger layout; we can agree on our own “standards” in this area but
these are probably a decent way to start.
The ballast recommendation for the “through route” (the mainline) is the same as the NWTM; it’s a
good look and if we do some joint sessions, things would look nice (and it’s easy to buy retail from
most any good train-oriented hobby shop so you don’t have to special order it). You are free to ballast
non-mainline tracks as you wish so feel free to use “cinders” on secondary trackage if you like and keep
in mind that being “free to ballast non-mainline tracks” also means that you don’t have to ballast at
all if you want to model an industrial spur that’s “down in the weeds” and set right on the ground.
RP6.6 Scenery shall generally be reflective of the summer season. [WCMRRA]
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7.0 OPERATING
Define how we will check out modules before first use
Talk about designing layout setups
Talk about measuring modules for accurate layout design
Talk about how we’ll get ready for setting up at shows and designing the layout
8.0 GLOSSARY
Branch line Module
Mainline Module
Mini Mo
A module whose end plates are narrower than the Free-Mo standard
specifies
Through Route
The route on your module that trains would take if any turnouts on your
module are positioned so that the train continues on the same track it
entered your module from one end to the other.
9.0 REVISION HISTORY
Free-mo Standards & Recommended Practices Revision History
2008-03-16 Updated the links out to the NMRA site to the new NMRA site.
Changed a comma to a semicolon in S1.1 "...emphasize realistic, plausible scenery; realistic, reliable
track work; and operations."
MENTION OUR EDITS
10.0 USEFUL REFERENCES
FREE-MO TIPS AND TECHNIQUES
http://www.trainweb.org/freemoslo/Modules/Tips-and-Techniques/index.htm
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