Fibre optic experiments

Jan 28, 2018

Played around with a strand of 0.75 mm fibre optics. The experiments is to see what can be done with the fibre to get different light effects.


Top left: normal light output.
Top right: I cut a v-knotch into the fibre with a knife, to bleed the light. some light carried across to the other side, but with less amount of light. I am assuming that several knotches along the fibre will show steps of light output. Possible optical foreshortening of street lights, etc.
Bottom left: I melted the end by carefully nearing the fibre end to a flame. This creates a lens. Actually, if you look into the lit end you can see multiple optical channels, like multi-strand wire. This enlarges the optical output diameter. Also, it could be used as a small porthole light, car headlights, or even a torch. The outside hole can be slightly countersunk to allow the fibre end to be snugly embedded.
Bottom right: Shaved a pointed end. The end looks matt white without a light, but lit with a light. Can be used as a pointer. Or, for a night time model scene as a firearms flash, or small tongues of fire, or a small scale candle.

Not all experiments worked. Here I was trying to bend the light at 90 degrees. The fibre itself can be bent at a very small radius (1-2 mm) but if you bend it passed 90 degrees it will break in half. Plastic does not make a prism, not even with foil as a reflector. One can cut the fibre at 45 degrees and super glue it together to make a 90 degree bend. This could be good to use for tight gaps. The light output is slightly less. The light bleeds out at the cut and join, or tight bend.


Experimented with the idea of an instrument light. It did not work too well. It could be better if the fibre end was fitted into the side of the plastic (dial) without using glue. Or have the fire light up the small scale instrument cavity between glass Plastic film) and the dial. Below, I used the triangle from previous experiments. I painted the sides black and the bottom triangular surface with white gloss.


Much more can be experimented with. I firmly believe that fibre optics, as a means of miniature lighting, can be a great novelty to models.
Hope these experiments will inspire those who have not yet considered fibre optics.
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Hi Swabbiie,

What is the source of light for the Fibre Optic.
Any light. But a small light source would be a Light Emitting Diode (LED). The optic fibre end is glued to the LED's brightest point (usually at its tip). If you need to know how to connect a LED to a power source, just let me know and I'll post that information.
Sorry about it being a bit out of focus.



That 1.5 volt test may not work these days, for modern LEDs have a slightly higher voltage for the diode to conduct. LEDs today have an operating voltage between 2 and 3.3 volts. Originally they were 1.7 volts. So, a 1.5 volt battery may not be enough to light a modern LED. If not, then add another 1.5 volt battery (in series) to make a 3 volt supply. That ought to be okay. Better still, use two NiCad batteries, for they are 1.2 volts each. That is 2.4 volts for two batteries in series.

I know that 5 volts will blow the LED.

You can always test the LED polarity with the power supply and resistor you plan to use. The point is, the voltage must be around 2-3 volts.
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Slightly off topic, but I’ve used RG (red/green) LED’s with my other hobby.

EAABC3D0-FD8B-43F5-845E-156CCF29426C.jpeg Control panel for a

switching yard on my RR layout. I think I will try to convert my panels to your fibre optic lighting method.
I really love your diagrams and drawings. Very nicely done. I wish that I could do that. Freehand even ? Just like an old fashioned Scientific Journal written by a scientist !!!

Wow, just what you could do with CAD in your hands. TurboCAD ?
...Just like an old fashioned Scientific Journal written by a scientist ..
As a boy, I used to buy secondhand Scientific American magazines. Not so much to read them, but to stare at how the artist illustrated the Amateur Scientist section in the magazine. I used to collect the images. It had a style of its own.

I still research how others present things. In the last two weeks I have been starring at the art of Chris Foss. His sci-fi illustrations are decades old, but still very much in vogue. But it is not that, it is his style. Recently I have a particular interest in his typography (markings on space ships). He has his favourite numbers and shapes and knows how to use them most effectively.

What I am saying, is that aesthetic style, particularly your own, can magically disguise imperfections. I believe this is also true in model making. However, to bring this out in a model often requires a slightly different approach to what everybody else is doing.