Saturday, April 16, 2016

Let There Be Light

This latest blog post is the 4th one detailing the construction of the layout, the 1st one detailing the construction was on February 19, so we are basically two months into the build, and I have to say that I’m very pleased with the progress that has been made so far, and particularly after this last three days of work, which has seen the layout transform.

In the previous post we had managed to get one of the Haskell back scenes in place, now the complete top level has back scenes the whole way around, which equates to just under 20 metres worth. These back scenes are extremely high quality and look brilliant once in place, but due to their length of either just over or just under 3 metres each, installing them in place is quite a tricky job.

I chose two different styles of back scenes, so as to give both sides of the layout a slightly different feel. The scene behind what will be Gunnedah yard is more of a hilly landscape, with the other side of the layout that will be the location for the abattoir and coal siding which are on the outskirts of Gunnedah is a much flatter landscape.

Obviously with two different styles of backdrop there could potentially be an issue where they joined together, however the two scenes managed to join together without clashing a great deal. Careful placement of some foreground trees should almost completely mask the transition between the two scenes.

Due to the construction of the shed, both side walls have a protrusion because of the framework behind them. We debated but the best way to deal with this in regard to the back scene, but in the end the decision was made to curve the back scene around the protrusions, which from most viewing angles very much disguises them and keeps the back scene flowing as best as possible.

With the back scenes in place, it was time to tackle the LED lighting. When I had decided to go with LED lighting, it all sounded pretty simple, by some five meter LED strips with power supplies, install the strips in place, plug in the power supplies and bingo, the layout is lit. The reality is somewhat more complicated.

The LED strips that I have chosen, consist of a combination of warm white, and RGB colour adjustable strips. Warm white strips give off quite a yellow hue, and cool white gives off more of a blue hue, neither of which look right. However, the combination of the two together very much cancel out either undesirable trait. Using the RGB adjustable colour strip gives even further adjustability in the lighting, being able to dim them slightly, and also being able to dial in slightly different colours where you may be able to replicate to a degree things like dusk or dawn, or even going a very blue shade which can go a way to giving the impression of night-time.

The biggest factor with the LED lighting, is that each five meter strip is rated as needing six amps, and whilst you can order of the strips with a six amp power supply, a quick bit of mathematics throws up the following:

To go around the room is just under twenty metres, there are two levels, and each level requires two different LED strips, which means sixteen five meter LED strips are required, and thus that would require sixteen six amp power supplies!

Adding to the complication, each RGB strip need a colour controller, and the colour controller they come with can only handle six amps, which would require the use of eight colour controllers. This was all beginning to sound a little bit nutty, and quite frankly a lot more complicated than it first seemed.

After spending a considerable amount of time looking into the RGB thing, I was eventually able to find some components that would make the installation a little bit easier, or at least slightly simpler with less components.

In the end I settled on using four thirty amp power supplies, and managed to find RGB colour controllers that could handle twenty-four amps, meaning that I only needed two of these to control the eight RGB strips.

Doing it this way meant that we only need two power supplies and one RGB controller on opposite sides of the room, much better than the sixteen power supplies and eight RGB controllers initially needed.

In keeping everything as easy to use as possible, a simple switch box is mounted underneath the bench work on two sides of the room, each has two switches on it which turn on and off either the warm white or RGB strips for half of the layout.

For the lower level, we mounted the LED strips on panels made from thin plywood, that were attached to the timber strip that runs around the front edge of the layout, using small 90° metal brackets, which we were then able to bend outwards so that the LED lights would project down on an angle making sure that the front edge of the lower level modules are lit properly.

For the top-level, the LED strips are mounted on a piece of triangular shaped timber (similar to a piece of quad with a straight and not curved section) so that they shine down at about a 45° angle. The combination of the two LED strips gives a more than adequate amount of light, and really makes the back scene come alive.

Standing in the room and looking around with the completed back scenes in place and LED lighting 95% finished was quite a big moment in the build. The basic layout looks good, but it now has a real sense of purpose, and if I may say so myself, looks absolutely awesome.

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