NEC Modular project

[Hiroe]

After some discussion with a few of the HO guys who are going to be participating, here's what I'm going to push for as standards:

- 4-track mainline
- C83 or larger rail size on mains, C55/C70 acceptable for other tracks
- 2" spacing on all mains
- No joiner tracks, run the rail right to the module edge, and use
brass screws into the end frame (or PC ties) to solder the rails to the top of for
strength
- Anderson Powerpoles for all individual-track-bus 2-pin connectors,
Molex 12-pin for corners and reversibles. (I can generate pinouts of
these shortly)
- 16 AWG wire minimum for mainline busses, 14 awg recommended
- layout wired for 2-rail operation, rails not bonded
- separate 2-wire bus for common catenary system
- module lengths in multiples of 4' or 5'. (I am personally building
5'x18" modules, but would have no objection to traditional 4'x2' ones, or 4'x18" hybrids)
- adjustable legs that can give rail height of either 40" or 52" from
floor (I have worked out the mechanics of how to accomplish this, and
will post details presently)
- corner modules built on 6' radius framing. (Mine are 30* arc
segments, and I have 5 of them, plus another 3 Y-junction modules that
fit the same 30* footprint, so we've got two full 90* corners
already.)
- strict limits on plastic wheels on the layout. We banned them from
the layout over at the Cherry Valley club, and it made a HUGE
improvement in the general cleanliness of the track. We now run the
track-cleaning cars about twice a year, instead of weekly.


Here's where I'm going with the ultra-lightweight modules:



These two are built almost completely with 2mm Luan birch plywood. The one on the right is still in the assembly jig. The only dimensional lumber they have is 1"x4" poplar on the ends (for clamping) and 1"x2" high-grade pine for the internal side glue blocks and the legs. The sides and interior framing is all 2mm luan as well, and they're assembled almost entirely with glue only, no screws except in the legs for reinforcement. The result is that they're extremely strong, while giving a considerable savings in weight.(About 18 lbs each, with legs.) Total hardware cost for each is about $60.

Here's two shots of one standing with the legs at 40" and 52" heights:





All the legs have 4"x 5/16" eyebolts for leg levelers at the bottom, as they're much easier to turn than the old carriage bolts (which would seize up and require a wrench).

Everything gets at least one good coat of Spar Urethane, for waterproofing and sealing from humidity changes. Side plates get 2-3 coats, for a furniture-grade finish.

30 years of East Penn module setups have demonstrated the usefulness of eliminating joiner tracks, and the soldered-to-screws/PC ties method gives enough strength and reliability that it should work quite well for our needs. This cuts way down on the time/aggravation at set-up, with only a touch more attention paid to rail alignment during clamping.

We also spent some time discussing placement of the catenary poles. We haven't settled on any hard-and-fast rules, but came up with a general guideline: poles should be spaced on the modules in a 1-2-1 spacing pattern, to give consistency in look across a run of modules. For 4' long modules, this is 12"-24"-12" (with the actual poles installed a foot from each end). For 5' long modules, this is 15"-30"-15". When placing a 4' next to a 5', it gives the result that the spacing across the joint has an intermediate step, in that it goes 24"-24"-24"-27"-30"-30"-30". This also ensures that any given module can be spun around 180* without impacting the overall appearance.

I have already worked out the issue of how to connect catenary wire across joints and give both decent appearance and effective pantograph function. I can describe the details of this if anyone likes, but it's easier just to show everyone when we reach that stage of construction.

[Hiroe]

As requested by several people elsewhere, here's a basic primer on how I built my module legs.

First, cut your 1x2" into the following:
8 each 30" long
8 each 6" long


Then, use a 1/4" drill to make holes at the following locations on each 30" board - 3", 9", and 21" from one end:



(If you want to make the legs fully adjustable from 40" to 52" (Useful for national setups in parking garage halls with sloped floors), just drill the legs every 3", starting at 3" from one end, and ending at 21" from the same end. This would give you a hole at: 3", 6", 9", 12", 15", 18", and 21". I may well go back and do this for all my module legs, so that way I'll never need spacer blocks to compensate for a badly sloped floor.)


Third, glue and screw each 6" piece to the long end of each 30" board, away from the three holes. Make sure that the screws are to the sides (not centered, as the eyebolt leg leveler will need to go there), and leaving 1" clearance at the end for the next step:


Fourth, cut 1" off the end of 4 of the leg assemblies, leaving the other 4 at full length:


Fifth, put one each short and long halves together with 1/4-20 x3" carriage bolts and wing nuts, like so:


Sixth, drill the 'long' end of each leg assembly with a 3/8" drill, 4" deep minimum, and install the 5/16-18 t-nuts and eyebolts:


Seventh, rip some luan into 4" widths, and cut 4 pieces from the 4" stock. I use 9" pieces for my corner legs; and because the legs for my straight modules lap within each other, I use both 12.5" and 16.75" pieces, Then glue and screw the luan plates to the top and bottom of each pair of legs:


Eighth, attach them to the module with strap hinges:



Last, install angle braces, to hold them open; and gate-hook hardware, to hold them closed.



--Drew

[Hiroe]

As I posted in the weekend update:

I recently rebuilt my curved-module-side assembly jig, and have started building the additional curved modules.

Photo time.

Here's the laminate jig:


One of the first ones out of the jig:




After a coat of Spar Urethane, and starting to lay track:


Here's one of the old ones I built 8 years ago:


These curved modules are simple and easy enough that it takes me approximately two evenings worth of work to go from raw materials to a finished module frame. Laying track and installing wiring is a third evening worth. I have yet to build the jig for assembling the catenary wire for the curves; but I estimate that once the jig exists, I could probably crank out the wirework in a single evening.

[Ian MacMillan]

This is going to be interesting!

[C855B]

Yes, very interested here, too.

What are you using to make the curved wood? Are you laminating strips of luaun? Or a veneer? It's not quite clear in the photos.

[Hiroe]

Yes, very interested here, too.

What are you using to make the curved wood? Are you laminating strips of luaun? Or a veneer? It's not quite clear in the photos.

Mike,
I'm laminating three layers of 2mm door-skin Luan plywood. I can buy this stuff in 4'x8' sheets (sold as underlayment grade), but it does have a distinct difference between the A and B sides. The A side is typically nice enough to give a furniture-grade finish, so I arrange the layers in such fashion that it's on the viewable side.

[Hiroe]

Typically, when I'm out shopping for Luan, I buy three sheets of 3mm for the straight modules. One sheet I have cut into 8' x 18" strips, one sheet I have cut into 8' x 4" strips, and one sheet I leave whole. Then, when I get home, I rip two of the 4" widths in half on a table saw with the rip fence set at a 1/32" less than 2", giving me four 8'x2" strips (approximately; cutting them a hair narrow will compensate for both the saw kerf on the rip, and any miscuts by the lumber supply).

When assembling an 18" wide module, I precut all the parts before assembly. Most of the Luan I use is 3mm, so I subtract 6mm (approx 1/4") from the 18" length for the 1x4" poplar end blocks; so that the luan sides will fit under the 18" deck piece.

The deck piece, I cut a 5' length out of one of the 18" wide stock. I draw out my track plan on it, and predrill any locations for switch motors with a 3/8" spade bit. This helps with assembly, so that I can adjust my bracing to fit around the motors.

Each lengthwise side I cut from the 4" stock, 5' long. This leaves a 3' piece of 4" stock, which I usually rip on the table saw to the same width as the 2" stock; although I will probably cut end reinforcements from it first in the future.

Each transverse brace (across the width) I leave whole. These I cut to 17.75" from the 2" stock, 8 each. In future builds, I will predrill these with a 7/8" spade bit for wiring holes at the following locations: 5" from each end, and dead center at 9".

Each end, inside the end frame poplar, I leave 8" for hand space so clamping isn't a pain. I double-up on the 2" framing pieces along the sides, just for a little extra strength, so cut 8 each of 8" long from the 2" stock.

For a 5' long module, this then leaves 42.5" of space between the clamp framing areas, of which 1.125" will be occupied by the thicknesses of the transverse braces. This gives 41.375" for the total length of all seven framing squares, so divide by 7, which works out to 5.91" per square (or roughly 5"+29/32"). I cut a total of 20 each from the 2" luan stock, and 8 each from pine 1x2" stock (for reinforcing the sides). In future builds, I will predrill 14 of these dead center with a 7/8" spade bit for wiring holes.

Then I glue everything together as seen in the photo above in my first post (using Elmers for wood or Gorilla glue), adjusting the framing as necessary for turnout motors.

If any of the transverse braces cross directly over a turnout motor hole, it's often easier to just install it as-is, and slide the tracks lengthwise along the module by 3/4", so the motor can then miss the brace. Keeping the tracks as-is and moving the transverse brace requires cutting new lengthwise strips for both sides, long and short, at 6"+29/32" and 4"+29/32" respectively.

For a 4' long module, cut a 4" long deck piece from the 18" stock, as well as a pair of 4" sides. We only need 6 each of the 17.75" transverse braces, cut from the 2" stock, and drilled for wire holes. The end frame clamping areas are the same, so no changes there. Our five framing squares work out to 5.95" each, or  5"+15/16", so cut a total of 14 each from the 2" luan stock (10 drilled for wire holes), and 6 each from the 1x2" pine stock. Assembly is almost identical to the 5' modules.

[C855B]

I presume you ease the cut edges with sandpaper or maybe a router for the laminated boards. My experience so far with lauan is that it is splintery and sharp, and generally a handling hazard if it's not laminated to something or the edges are rounded.

[Hiroe]

I presume you ease the cut edges with sandpaper or maybe a router for the laminated boards. My experience so far with lauan is that it is splintery and sharp, and generally a handling hazard if it's not laminated to something or the edges are rounded.

I've been gluing the crap out of everything, using a router to trim the deck pieces to exact size, using a palm sander on the whole exterior of the frame before the urethane coat, and re-sanding between coats to hit any rough areas as the grain rises. Which collectively results in a smooth, beautiful high-gloss finish on all of the exterior parts, and rock-hard internal framing, with no problems with splinters.

[sd80mac]

Hi Hiroe,

Did you notice any springback of module components once the assembled module was removed from the alignment fixture?

Donnell

[Hiroe]

Donnell,
There's minor springback of the sides if you remove them from the jig without assembling them to the ends and internal struts. However, I use the jig as a guide to get the frames assembled as a whole, so they maintain the proper shape after that.

Using the thinner 2mm luan has actually helped significantly in this regard. Back when I used 3 layers of 1/4" luan, the springback was big problem, and required gluing them with an additional 6" of radius overbend to get them to give the proper shape once released from the jig. Now that I'm using the thin stuff, the overbend isn't required.

--Drew

[sd80mac]

Thanks. I believe I found the method I'm going to use to build my free-mo curves! Also, could you give some insight on the PC ties at you intermodule joints.

Donnell

[Hiroe]

Thanks. I believe I found the method I'm going to use to build my free-mo curves! Also, could you give some insight on the PC ties at you intermodule joints.

Donnell

Donnell,
Originally I had been using 1/2" (or 3/4") brass #4 wood screws into the frame at the ends, with the rails soldered to the tops; but recently changed to using American Tie and Timber "Gapmaster" PC tie assemblies at the ends. This photo shows both:



The "Gapmaster" tie assemblies were originally intended for keeping rails aligned when cutting insulating gaps in flextrack, but I find that they're also great for keeping rails aligned at module joints. They're already set up with a break in the cladding to prevent rail-to-rail shorts, so pretty much all I do is lay out their position with a scale rule, glue them down with thick CA, and solder the rails to the top. Then once they're painted to blend with the flextrack, they're not nearly as obvious as the brass screws are. They also give a much more consistent height than the screws, as well as assuring that the rails are truly square with the module end.

--Drew

[Green_Elite_cab]

Donnell,
Originally I had been using 1/2" (or 3/4") brass #4 wood screws into the frame at the ends, with the rails soldered to the tops; but recently changed to using American Tie and Timber "Gapmaster" PC tie assemblies at the ends. This photo shows both:



The "Gapmaster" tie assemblies were originally intended for keeping rails aligned when cutting insulating gaps in flextrack, but I find that they're also great for keeping rails aligned at module joints. They're already set up with a break in the cladding to prevent rail-to-rail shorts, so pretty much all I do is lay out their position with a scale rule, glue them down with thick CA, and solder the rails to the top. Then once they're painted to blend with the flextrack, they're not nearly as obvious as the brass screws are. They also give a much more consistent height than the screws, as well as assuring that the rails are truly square with the module end.

--Drew

Ah, this does look a LOT better than the screws did! 

[Hiroe]

So, it's been five and a half years since I looked at this thread, and we've made significant progress:

I have a new jig for assembling corners and wyes:
https://photos.app.goo.gl/jtSSDwOWKOrE9j3E3
Using this, I can now assemble a corner or wye in about 35 minutes, and then just set it aside for the glue to cure overnight. This means that now I can crank out four or six in an evening, instead of just one a week.

Similarly, I can also build the straight modules in about 25 minutes each now, and I'm not even using a jig anymore. However, I've simplified them, so there's not 70 small pieces of 2mm luan to cut, either.
https://photos.app.goo.gl/FQIyxIUlIwhpDoyl1

I have some new corner sizes:
https://photos.app.goo.gl/RWiL7JgFdnzyjpcm2
https://photos.app.goo.gl/vgRxligIbGrVfWz83
These are 24" deep 30* corners with a 66" Radius centerline. In N scale, three of these would be a "6.5-foot" corner.
One of them is framed up with Free-Mo compatible endplates; although the Free-Mo groups have recently found us to be too radical for them to want to set up with us anymore.


One of the members of the group ordered this piece of work, as the first of his own loop of modules:
https://photos.app.goo.gl/k2fxJsJjkLmXnRVn2

We had the chance to set up at the RR museum of PA:
https://photos.app.goo.gl/mwvGZqFwvReDVV3i1

Greys Ferry is looking pretty good:
https://photos.app.goo.gl/tSA21YLq3EHSRdQo2

I have catenary work in progress:
https://photos.app.goo.gl/H6SaScBtcXzZOF9B3
https://photos.app.goo.gl/igezhfFcNVzi24B82

Silverliners:
https://photos.app.goo.gl/0XpiQHLlbrWO9vyS2
https://photos.app.goo.gl/HzubNYDYEf1eixzn2

Videos: