Carpentry
There is good inspiration to be found at www.stahlbahn.de.
The layout shall be build on a frame of good quality wood in reasonably small dimensions. I have thought of some premium quality 21×43 mm with a price tag of 115 kroner for 3,3 meter. But first I will try out 10×100 mm of a cheaper quality for about 1/3 of the price.
The lowest track is to be mounted directly on the frame. Track at higher elevation as well as landscape must be placed on blocks of wood or similar.
And to save a few precious centimeters, I will be placing the ECOS in a drawer underneath the layout, so that it doesn’t take up any space when the layout is not in use. For this, I am going to use these rails.
The track is to be placed on plywood. I will probably just buy a sheet or two in Silvan. First, I must find out if 6 mm is enough. But I am fairly certain that it is. It seems stiff enough. A sheet of 6,5x1220x2440 mm is 150 kroner. If it must be absolutely perfect, I might consider 3 mm plywood in premium quality from Krydsfinerhandelen in Rødovre. Witzel Hobby does also offer a selection. But it is expensive.
I will start with the frame. Then plywood and track for the first 1½ level, i.e. not for the track from Skive to Spøttrup. The plywood must be cut into strips only a couple of centimeters wider than the track. Then these plywood strips must be mounted with the correct slopes and elevations. I have read a bit of good advice at stahlbahn.de and I have seen pictures of the shadow station at kamstrupvej.dk, which together has lead me to these conclusions:
- I will primarily use 10×60 mm wood, even though it is expensive.
- The plywood (6 mm) must be attached to a wood strip on the wide side of the strip.
- This wood strip must be perpendicular to the track.
- To ensure perpendicularity, wedge shaped wood blocks must be used at slopes.
- Wood strips and plywood must be glued or screwed together so that the plywood can be forced both upwards and downwards.
- The wood strip underneath the plywood must be attached to “the pillar” with only one screw into the end of the wood strip so that it can follow the slope of the plywood.
- “Pillars” may be made from almost any pieces of wood that is available.
- I assume that a distance of about 30 cm between pillars is suitable.
- As much as possible is only attached with clamps or similar until the proper elevations and slopes have been found. Then it is attached with screws. AND THIS SHOULD PROVE ITSELF IMPORTANT LATER ON: IF NOT EVERYTHING IS SECURED TIGHTLY IN THE ABSOLUTE CORRECT HEIGHT AND SLOPE, THE TRAINS WILL DERAIL!!!!
Then comes landscaping in terms of 3 or 4 modules. And as part of those modules the track between Skive and Spøttrup. It is going to be challenging to make the modules fit so precisely that I can cut the track between modules and still have trains driving across modules.
The skeleton of the modules must also be made of wood strips. Maybe again 10×60 mm for the base parts.
A proper module size must be small enough to handle and big enough to ensure that houses etc. does not span across modules. Maybe 60 cm wide and deep enough to reach from Skive H and all the way to the back wall.
All electrical connections to a module must go via a single 25-pole connector. This is to ensure that it is easy to add or remove a module from the layout.
Since there is never enough room on a layout for all trains, I also need a showcase to store those trains that are not in use. The showcase shown here seems good and cheap.
As part of the landscape, I need a road for my Faller car. I am not yet sure exactly how to construct the road. Maybe just strips of 2 mm cardboard? It would be reasonably easy to work with – including making a groove for the guide wire, if it is not sufficient to tape it to the rear of the cardboard. Faller suggests 3 mm plywood. For that something similar to Faller’s own groove cutter (775 kr) is needed. Or one could buy Faller’s “laser street”. Or I could copy Jørnebanen, who on top of a sheet of plywood puts first the green parquet underlay and then what he calls “thin plastic” with the guide wire taped underneath. I don’t know exactly what this plastic is. Maybe some thin Evergreen sheets? Or these.
A crossing between road and railway is also part of the Faller kit. I will try to make room for that as well.
I have seen different methods for making terrain. It can be made from polystyrene sheets (that is strong enough to build houses on). Or it could be chicken wire and plaster or paper mache. In any case a wooden framework is needed underneath. See this video with chicken wire and plaster. Or this series about building in modules.
When all the basic landscaping is in place, the basic decoration can be done with sowing grass, painting the road (with wall paint?), painting track to become rusty, ballasting track and so on. That brings us to a steppe level.
And then we are ready to start putting signals, house, bridges, hedges, figures on the layout, sow corn and vegetables etc. a lake with water etc. etc.
Electronics and Wiring
On my prototype layout I have just been placing my electronics underneath the board wherever there was room for it. And all wiring is hung on hooks. All wires are “sufficiently thick” (0,75 mm2).
That will not work on a layout that is not built on a board and where I need to access it from underneath.
I will switch to thinner wire, the electronics must be mounted on a separate board on the rear wall and all wires must be marked in both ends so that I what is what.
On the prototype, I have switches to select between normal power and programming track power for the programming track as well as for each servo/turnout decoder.
With more decoders, that is going to be confusing. It will be better to make a switch board using a number of connectors.
I have bought RCA sockets from Reichelt. There are 4 on a small plaque. One socket shall be connected to programming power from ECOS, one to programming power from IB-COM. The rest is for normal track power from ECOS (for servo/turnout decoders) or from IB-COM (signal decoders and other “utility” decoders). Each decoder as well as the programming track is equipped with an RCA connector that is normally put in a socket with track power, but can be moved to one with programming power for programming.
The wiring from the electronics board and to specific spots on the layout must also be thought through:
Turnouts: A decoder is places as close as possible to the 4 turnouts it controls. That way only one double-wire need to go from the electronic board and to a place near the turnouts.
Feedback: The S88-N signal (ordinary network patch cable) is not noise sensitive. But the ordinary S88 signal, i.e. the cable between ECOS and the S88-N-P module is. So the S88-N-P module is placed close to the ECOS.
Track power: A rather thick (1 mm² or 2×0,75 mm²) wire for ground connection ought to be made throughout the layout. From this “bus” a thinner wire must go to the track approximately for each block. The “+” wire from ECOS must be passed through the current sensors, which are placed along with the S88-N modules on the electronics board. I.e. one 0,5 mm² wire must go from the electronics board and out to each individual block.
Opinions vary regarding wire thickness. And then there is this page, which is not just an opinion, but rather fact based: http://www.modelskibet.com/tips-tricks/ledninger/
If I calculate with the longest wire being 2,5 meter and a current draw per locomotive of 1 A, I get:
I am using a 0,5 mm² wire, which means an internal resistance of 0,0175 Ω × 2,5 meter / 0,5 mm² = 0,0875 Ω
With 1A through the wire, this means that the power being dissipated in the wire is 0,0875 Ω × 1² A = 0,0875 W
A power less than 1 W is OK.
The voltage drop will be 0,0875 Ω × 1 A = 0,0875 V
I.e. if the voltage out of the ECOS is 18 V, the locomotive will get 17,9 V (a loss of 0,5%), which is absolutely OK.
With 0,14 mm² wire, the figures are: Resistance: 0,3125 Ω. Power: 0,3125 A. Voltage drop: 0,3125 V. That could be OK for a servo or similar that does not continuously use power. But for the track, it is at the edge of not being OK.
I am considering to options regarding the installation:
Option 1: Wires soldered to the track shall only be 10 cm long and then be joint using screw terminals to longer wires. That would help if track needs to be removed for repairs.
Option 2: Wires should be long enough to go all the way. If the track need to be taken out, just cut the wire and re-assemble using screw terminals.
Option 2 seems best, but probably also most time consuming.
Signals: This too calls for decoders close to the signals. 1 decoder per signal. The power supply part of the decoders can be comon for several decoders. This common power supply shall be placed on the electronics board.
The Electronics Board and Main Diagram
Since the decoders and the S88-N-P module are placed elsewhere, the electronics board must contain the following:
- IB-COM
- Transformer for IB-COM
- Raspberry Pi
- Maybe additional Raspberry Pi for intelligent control of night and day, light etc.
- Ethernet switch
- Transformer for ECOS
- “Switch board” for decoders and programming track
- Power supply part of signal decoders
- 3 S88-N modules including current sensors
- Loconet feedback module for switch buttons, reed switches etc.
- Power supply for LEDs etc. in turnouts, houses and so on
- Maybe electronics for crossing between road and railroad
- Power rails for all of the above and more. At least 12 outputs.
The board must be designed for simplest possible wiring.
The new main diagram looks as this:
Ensuring Complete Trains
Another important issue is feedback on the shadow stations: I am considering the importance of ensuring that the last wagon in each train is coming into a block – especially the destination block. For that, I am considering an extra kind of sensor beside the current sensors. And since it must be something that only detects the last wagon, my only idea at the moment is reed switches and a magnet at the rear of the rear wagon. My Jython scripts must then check these reed switches.
The last wagon must also draw current from the track, i.e. be equipped wit a collector shoe, so that JMRI can see that the block where the last wagon is, is still occupied. If not, the risk is that a signal is set wrong and a block is de-allocated to early and thereby trains collide.