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Signal LED's

3K views 12 replies 5 participants last post by  serridger11 
#1 ·
Hello everybody could anyone help me, you see im putting lenses in my signals Im making (00 scale) so i need very short LED's for them, does anyone no where I could get such LEDs.

Richard
 
#2 · (Edited by Moderator)
Hi and welcome to this specialist bit of the Forum.

If you are talking about semaphore signals, then several of us use 1.8mm LEDs, sometimes known as 'top hats' and reduce the front down a bit. I think if you look at one or two of Lancashire Fusilier's pictures you'll see he's used them. We solder on fine wires and then cut the LED leads as short as possible.
They are available from All Components, Electronix Connections and others - possibly also Maplin. I'd post a picture or two myself but having problems at the moment downloading to my Photobox albums.

If it's colour-light signals you are making then there are small round (2mm) leds available, although I've not bought any myself.

Regards,
John Webb
 
#4 ·
You need 3mm outside diameter plastic tube - this should be just slightly bigger on it's internal diameter than a 2mm LED. I'm sure I've seen an article recently about modelling colour-light signals - if I remember where I saw it I'll post details here for you.

Regards,
John Webb
 
#7 · (Edited by Moderator)
QUOTE (John Webb @ 21 Sep 2008, 04:18) <{POST_SNAPBACK}>You need 3mm outside diameter plastic tube - this should be just slightly bigger on it's internal diameter than a 2mm LED. I'm sure I've seen an article recently about modelling colour-light signals - if I remember where I saw it I'll post details here for you.

Regards,
John Webb

***Actually from the dimensions I have for hand making accurate colour light signals you do not need short LEDs at all.

You need bog standard 3mm T-1 type LEDs and 1/8 ID brass or fine wall plastic tube.

Richard
 
#8 ·
QUOTE (Richard Johnson @ 21 Sep 2008, 06:28) <{POST_SNAPBACK}>***Actually from the dimensions I have for hand making accurate colour light signals you do not need short LEDs at all.

You need bog standard 3mm T-1 type LEDs and 1/8 ID brass or fine wall plastic tube.....

Richard, is the design of signals 'down under' different to the UK? Just that 3mm=9inch scale diameter - but from British sources and actual measurement of a three-aspect colour light head given to St Alban's Signalbox recently, the UK ones seem to be 6inch/150mm diameter, implying the use of a 2mm diameter LED to keep in scale.

Regards,
John Webb
 
#9 ·
Below is a link to the standard for UK signals:

http://www.rgsonline.co.uk/docushare/dsweb...399/Rt0031a.pdf

Diagram on page 7 shows lenses to be 200mm diameter (8" approx) and at 255mm centres (10" approx). I also measured one (undefined provenance but presumably elderly) at Crewe Heritage Centre which was about the same as this. So although some older ones could be smaller I suggest Richard's 3mm LEDs are about right for modern UK signals in 4mm scale.
 
#10 ·
QUOTE (Edwin @ 21 Sep 2008, 18:59) <{POST_SNAPBACK}>......Diagram on page 7 shows lenses to be 200mm diameter (8" approx) and at 255mm centres (10" approx). I also measured one (undefined provenance but presumably elderly) at Crewe Heritage Centre which was about the same as this. So although some older ones could be smaller I suggest Richard's 3mm LEDs are about right for modern UK signals in 4mm scale.

Thanks for that - it may be that the one prototype I've looked at closely is an older model, but at 8" the 3mm LEDs are certainly a closer match for the modern ones.

For models, the LEDs do look better if the dome on the front is flattened as much as possible as the curvature on the lens front is not great on the prototypes. Careful filing and then polishing on 1200 grit wet and dry paper gives quite a good appearance.

Regards,
John Webb
 
#11 · (Edited by Moderator)
QUOTE (John Webb @ 22 Sep 2008, 06:56) <{POST_SNAPBACK}>Thanks for that - it may be that the one prototype I've looked at closely is an older model, but at 8" the 3mm LEDs are certainly a closer match for the modern ones.

For models, the LEDs do look better if the dome on the front is flattened as much as possible as the curvature on the lens front is not great on the prototypes. Careful filing and then polishing on 1200 grit wet and dry paper gives quite a good appearance.

Regards,
John Webb

*** I was referring to UK signals when I wrote the post John - As a healthy part of my business relates to accurate scale lighting, if I ever quote other than UK stuff on a UK forum, I'd say so


I've much more data on UK signals than I have for AU prototypes.

Actually all over the world the conventional style colour light signal uses quite similar sized lamp lenses with few exceptions, just as the lamp colour (tint) for red, green and yellow are similar as they tend to have standards that once generated in one place, are promulgated elsewhere....so as a result, in many cases the signal parts supplier is the same for many countries too.

As to flattening the LED front, even though I am a stickler for detail I'd have to say it is a lot of work to not much good purpose... if they are correctly seated within the shroud on an accurately built signal then there is, once established on the layout, no real practical or even much of an esoteric visual benefit - if someone is so bored with the general scene that they become fixated on looking at the light lense shape, then either they have no ability to appreciate a scene as a whole or the rest of the signal and layout would have to be very mediochre or boring indeed.

Richard
 
#12 ·
Richard, all your comments noted with interest.

The article I was thinking of was by Tony Sissons in Model Railway Journal 171 regarding the building of a bracket signal. But he doesn't actually say which LEDs he used and refers back to a previous MRJ 161 article, which I don't have!

Regards,
John Webb
 
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