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Just another modeller
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QUOTE (beast66606 @ 13 May 2008, 18:33) <{POST_SNAPBACK}>Dependant upon the date your model is based on an LED would be far too bright - oil lamps were very dull and when the spectacles got dirty they got even duller - until the lamp man gave them a wipe on his rounds.

The general proposals for powering the lamp look good though.

Some very early signals were gas lit which gives another excuse for a "wire" down the side

***With 12v and between 12 and 15k the LED will be just fine - Several of the best Pro builders in the UK do just that, as do eveyone else I know who makes signals.

The best way to try the reistor value is to buy a 20K linear potentiometer. Put a ik resistor in series with it as a "safety net".

connect it in series and twiddle the knob until you have the light level you want, then take away the power and measure across the potentiometer terminals. Just use the nearest (next highest usually) standard resistor value and you are done!

with a high value resistor it will be limited to a milliamp of so as will barely glow. If its still slightly bright paint the lens with a mixture of clear varnish containing a very little black and orange - it softens the colour even more and gives a smoky tint thats actually rather neat.

for the wire find a dead motor - old shaver, dead model railway motor etc. the motor winding wire is super thin (hair sized sometimes) and is enamel covered. You'll need to strip off the enamel of course to solder to it - use a strong solvent.

Option - I sell a silver loaded paint - Martin71 has an image on forum somewhare showing a lamp in the hand of a 4mm scale guard - he painted the wiring onto the figure with the silver loaded paint then painted his clothes over it when it was dry - totally invisible.

BTW - paint the LED all over white or spray with standard gray car undercoat...(it reflects light inwards and helps reduce leakage better than a black base coat) then paint the final colour on top of that. to make the clear lens, file across the face of the 1.8mm microdot and you'll get a perfect round shape - much easier than painting it neatly :) :)

Regards
Richard
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QUOTE (John Webb @ 13 May 2008, 20:26) <{POST_SNAPBACK}>Some signal lamps were electrically powered, but often oil-lit signals has wires running up the post to connect to a switch indicating the arm position back to a repeater in the signalbox and also connections to a bimetal strip in the oil-lamp - if the lamp flame failed and went out, the bimetal strip cooled down and broke a circuit which then alerted the signalman that the lamp had gone out. Such devices were in use from around 1850/60 onwards, so wires on signal posts are truely prototypical.

Regards,
John Webb

*** I didn't know about that bi-metal strip John - thanks for the very interesting bit of Information!

Richard
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QUOTE (beast66606 @ 13 May 2008, 23:04) <{POST_SNAPBACK}>Be interested to seem some photos of those - from my observations most model signals are far too bright, whoever makes them, and as I photographed probably the best part of a thousand prototypes I have seen one or two of the real thing.


***I haven't any installed yet but when I do I'll take a photo - the LED is really only just adequately powered to turn on... they are pretty well invisible as far as light is concerned in daylight, with a soft glow in softer light - I too know what they should look like!

Bear in mind they DO in reality have to be very slightly brighter than the original of they'd never transmit through the spectacle at all on a model!

Not quite the same thing, but here are a couple of led images taken with the lights off early in the development of my loco lamps on a part finished model - even though they are still totally bare LEDs you'll notice there is not enough light to illuminate the buffer beam - and this is before the tinted epoxy (smoky amber/yellowish) lenses are added in front of the tiny 0.8mm LEDs - once finished, they are indeed like paraffin or oil lamps. The resistor in this case is 14k from memory

Richard
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QUOTE (beast66606 @ 14 May 2008, 17:19) <{POST_SNAPBACK}>Richard, you LEDs look good but a bit white I assume your comments about masking them will be applied.

*** As I noted the image was to show you that an LED can indeed be attenuated to the point that it has the correct level of light. The white balance of the camera was still set for some product photography rather than natural light so that + the slow time of that exposure made them look whiter than they really are (they are actually golden/prototype white) however as I noted in the same post, they were also photographed without the lens which I also add/make from tinted epoxy being applied to them - they look exactly like an oil/parrafin loco lamps softer tint when its in place.... I am very particular about such things

Richard
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While I think about it...

at the time of the grouping there was a really unusual signal at one end of Ribblehead - two arms on the same post but most unusually, one facing in each firection on opposite sides of the post. I presume it was done that way by the Midland because of sighting needs but it was a rare and very non standard sort of arrangement. The LMS replaced it not all that long after but I'd like to model it as it still was in 1928.

Does anyone have any good images of that signal? The only ones I can find so far are very much in the distance and not good enough to calculate height and detail well enough to satisfy me.

(For that matter I'd be grateful for any added detail or signalling diagrammes for Ribblehead stn, Blea Moor, Settle and Stainforth boxes as I'd like to recreate the original signalling + original box diagrammes on the computer screen I'll be using for each of those places on the layout - the layout will in fact be touch screen controlled from those diagrammes)

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Richard
 

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***More like me hijacking your thread Paul - Its I that should be saying "Sorry"

Re other S&C box info - thanks to both of you - I have the Anderson/fox book and a selection of about 20 other S&C related books of various vintages all with some data plus perhaps a dozen related S&C station / signal images from the HMRS - but as noted, the signal diagrammes in Fox are much later than my modelling period so I was hoping to one happen onto the pre-ww2 diagrammes one day.

The line was quite different before BR as there were no loops of facing points at all including at Blea Moor until mid WW2 making (I presume) many of the siding related signalling situations slightly different... and thats the way I've built it with the only exception being a single change each at Stainforth and Settle where I've turned a single slip into a double slip to make operations a wee bit easier for guests.

What I may do one day is cheekily ask 'Expert John" for a suggested signalling change so my model mirrors reality but also reflects my layout trackage properly, as I only know enough to be in danger of silly errors when it comes to that subject!

Re the signal on Ribblehead I had read that it was replaced by the LMS before WW2 with a more conventional 2 arm (one above the other) signal with the arms correctly on the same side of the post and it looks like the signal was also reconstructed much taller to improve sighting but thats not important - I was hoping that there may be better pictures of the original, and anyway, you may well be 100% right anyway as my only source for the data is an extended caption to the viaduct photo...and photo captions are often slightly wide of the reality.

The only thing I can be sure of there is that if I guess, just as I finish it a new photo will arrive to annoy me over the slightly incorrect details :).

Paul - ou've doe the LED exactly as I use the 1.8 - it works well doesn't it! if you want to email me a photo I can post if for you. The wire by the way is Kynar - silver plated, very fine with the thinnest possible insulation.

Richard
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