A Dog-bone N Scale Layout

Recuperating from eye surgery, I had a bit of time on my hands. My thoughts turned to building a layout that is in the house instead of being stuck in a cramped garage. Besides, a new wooden train set from Ikea for my three year old was making me envious.

We have a wall unit in our family room - the top of it is long and narrow and is largely occupied by two hi-fi speakers sitting on their sides. I had the following objectives in my mind for the new layout.

Layout Design

The top of the wall unit is about 460 mm x 2800 mm. It is 1700 mm above floor level. The two hi-fi speakers at each end have a footprint of 600 mm x 300 mm.

A dog-bone seemed to be simplest shape that would fit the target area. This would keep the initial construction and operation simple. A minimum turning radius of 280 mm(11") would be used. This will mean the end loops will stick out beyond the edge of the unit. One leg of the dog-bone will run along the front edge of the unit and the other along the back edge. The space between the two edges may become a yard in future. In order to use the entire length, the track has to run under the speakers.

The baseboard will be designed to be modular. This will allow a section of the layout to be taken off the top of the unit and worked on. It will also allow expanding the layout by replacing one section with another.

Layout Diagram

The baseboard is in four sections shown in blue - the two ends and the two straight sections connecting the two ends. The front-edge of the baseboard projects out about 100 mm beyond the front edge of the unit. The hi-fi speakers are above the ends elevated 50 mm above the baseboard surface on square posts. Transition curves are used at suitable places to reduce lurch.


I had a suitable piece of 12 mm ply to make the baseboard. The track used is Peco flex track(SL-300 Code 80). I used Peco foam underlay which I had on hand. It doesn't look good and handles even worse but I had lots of it to use up and it would save some time.

Using an additional layer over the baseboard to hold nails was avoided for aesthetic reasons and simplicity. Instead, I used a technique I've used before. Using a power screwdriver and a small chuck, I drill a 0.7 mm hole through the tie and into the ply. I then push an Atlas nail through the hole.

I glued small squares of 3 mm MDF under the baseboard to create a small gap between the baseboard and the top of the unit. This space is used for wiring. I used larger squares directly under the speaker supports to take the weight of the speakers without buckling the ply. I used a thin speaker cable for the wiring. It is thick enough, comes in a figure 8 and has a black line indicating polarity. I run the wire along the track and attach feeders to the track at 400 mm intervals. This should reduce voltage drops along the track. I intend to use connectors at places where two sections of baseboard meet.

Layout Control

I don't have any N scale DCC decoders yet. To start with, I will use one of the HO scale DCC decoders I have on hand and power the entire track with it. I can use only one loco this way.

I am planning to buy the new Lenz LE077XF decoders from the US by mail order. They go for about US$25 and should fit into the few N scale diesels I have.

I intend to dust the cobwebs off my DCC control station and hook it up to the track. The VB front-end for it has long been replaced by a java front-end. The basic communication with the command station is working and I will continue enhancing it as I go along. I am hoping that the presence of this layout right above my PC will inspire me to resume my work on the DCC project.

My previous half-built N scale layout in storage can now be put out of its misery.

Progress - 2007

Over the years, I have moved house. Parts of the dog-bone layout were lying in the garage for a few years. The wall unit and speakers were still in use. So, recently, I pulled out the layout and put it back together on the wall unit. I also took a few pictures of parts of the layout. It seems to have survived the few years sitting in the garage pretty well. The track had not lifted off inspite of the unorthodox method of fixing it down. A quick run over with a vaccuum cleaner cleared off the layer of dust.

I put the track back on the wall unit. This time, I put small pieces of Blu-tac under the board. This should prevent it from shifting due to small bumps to it. I also took some photos of the track.

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Pic 1 - Top of track Pic 2 - Bottom of track

Pic 1 shows the top of one end piece and one straight track. The four posts supporting the speaker can be seen on the end piece. Pic 2 shows the underside of the same. Small squares of MDF to maintain the gap for the wires can be seen. The bigger squares are under the posts supporting the speaker. The wires have been taped to the underside. Connectors at the ends of the wires are used to electrically hook them up together.

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Pic 3 - Joint between pieces Pic 4 - Underside wiring detail Pic 5 - Closeup of track

Pic 3 shows the joint between two pieces. Rail joiners join the ends of the rails. Electrical connectors seen in the background hook up the two sets of wires. Pic 4 shows the detail on the underside under the tape. A solid piece of wire goes from the two wires through a hole to the track. This wire is soldered to the outside of the track. The joint is then tapes over. Pic 5 shows a closeup of the track. The nail holding the track down can be seen clearly.

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Updated on 21 Mar 2007. Feedback to