Using LED's in/on rolling stock.

I'm something of an experimenter when it comes to making something a little out of the ordinary, and LED's present a useful way of adding lighting to rolling stock, adding a bit more realism, especially to night time running. On my layout, I have around a hundred LED street and building lights which make running in darkness completely different to daylight running, 2 transformers being used just to power these lights. When it comes to installing in rolling stock, it takes a bit more thought to install lighting, not as much space available for a start, but here's how I've tackled it. As an example, my Lima Class 33's have more internal space than many models, but it's not easy to fit LED's into the front and rear light positions as it's a bit cramped in that area, so I resorted to using Optic Fibre in conjunction with the LED's. In the pic, you can see how the dual red/white LED's are mounted opposite each other on a small piece of Veroboard (not forgetting the necessary resistors!) 'Blu-tacked' to the loco's roof, fibres being 'Blu-tacked' out of the way of the motor, allowing it to pivot without obstruction.

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Hopefully, this pic shows things in a little more detail.

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I've tried 2 different ways of attaching the fibres to the LED, first way is using a bit of 6mm white plastic rod, drilled about 5mm deep centrally with a 3mm hole to accommodate the LED. At the other end, I drilled two 1mm holes at a slight angle, joining together into the 3mm hole at the other end. Inserting and gluing two 1mm optic fibres into those holes, butting up against the 3mm LED glued into the opposite end resulted in excellent light transmission down the fibres from the LED. Hopefully, this pic should show what I mean.

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I'd suggest using a pin vice to do this drilling, a slip with a Dremel or similar could be painful! As an alternative, I also tried filing a chamfer on two pieces of optic fibre to blend them into one before gluing together, and as 'belt & braces', binding them with fine jewellery wire as in this pic.

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Once glue has set, I joined LED and optic fibre with heat shrink sleeving. This not only securely attaches things together, it also prevents stray light inside the loco body. If you use method 1, you will need to use either suitable heat shrink or alternatively black Electricians tape for the same reason.

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Once this is done, it's out with the soldering iron, and connect to the decoder, positives go to the Blue wire, forward lighting on the white, reverse on the yellow, not forgetting that you need to connect front white light to rear red light connections, and vice-versa! Here's what it looks like when done.

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.......and in reverse direction-

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So now, from a loco to other rolling stock. You really don't need to be brave to dismantle carriages, guards vans etc. since they are mostly clipped together on the production line, and come apart fairly easily. I've built many small circuit boards and pickup assemblies which I've fitted into all stock needing lighting added, and it's really a standard unit, cheap to build, gives you soldering practice (or burnt fingers!) to boot, and keeping it small means they normally fit into carriage toilet compartments or corridor ends. Here's a pic of my 'standard units'.

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When it comes to carriage lighting, I buy 5 metre strips of 'Warm White' LED's on a roll. Don't use 'White' as it's a rather 'blue' light which resembles the colour of Mercury Vapour lighting......not what you want! I glue a strip of white paper about 30mm wide, down the middle of the inside of the carriage roof, which helps prevent stray light up through the roof itself, then stick the LED lighting strip down the centre, having soldered on your connecting leads. These go to the circuit board output, inputs to this come from the pickup assembly glued to the underside of the stock, brass strips bearing onto the inner edges of the stocks wheels. This pic gives the idea.

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And a completed rear end shot.

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A guards van given similar treatment.

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To make the 'loco lamps', I use what I'd describe as the 'block type' LED's, gluing on a small strip of brass to make a 'carrying handle' at the top, then a couple of coats of white (or occasionally, black) paint, necessary again to stop stray light,- after all, you only want light showing out of the 'lens' of the lamp. I've 'lashed up' a couple to show the sort of thing I mean.

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.....and a rear lamp.

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I'm aware that my 'take' on this isn't exactly 'ground-breaking', and lamps are available anyway, but you can make 'my' sort of lamps for literally pence, whereas if you really want to go out and buy some, from my recollection, you're looking at about a 'fiver' apiece. Adding lighting to both rolling stock and buildings adds a different dimension to a layout in my opinion,- I've not (yet) gone as far as adding LED's to motor vehicles on my layout, and I know some are already available, but maybe in the future.....?
Keith.

 

I couldn't find where I'd put the circuit for supplying DC from DCC track voltage, so I had to draw it out again. Sorry if it looks like a spiders crawled across the page, I'm no artist and my handwriting has never been "Copperplate", but here it is. I've photographed it with an actual completed circuit board and a ruler for size comparison, although if you were really tight for space, it could be made even smaller. The capacitor is partly for voltage smoothing, but does give a small amount of 'stay-alive' ability. Subject to having space to put them, there's no reason why you couldn't incorporate more/larger capacitors to increase 'stay-alive' time. Note that I still use a 1k resistor in the +ve leg of any LED I connect to this circuit in addition to the one on the circuit board! Regarding the long term 'stickiness' of 'Blu-tack', my Class 33's have been lighting fitted for a little over a year, and the 'tack' shows no sign of letting go. If you use the optic fibre for any project, then don't use cyanoacrylate glue on it as it weakens it,- I've used "UHU' clear all-purpose adhesive from the 'pound shop'!
Keith.

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