Using Fiber optic for rolling stock lights

[gdelmoro]

Hi I want to create a Christmas train using LEDs and fiber optic strands.

I understand the concept but how do you link the fiber to the LED light source?

These are created this way

[7j43k]

Sounds like fun.

(The example photo isn't opening for me.)

Until someone comes in with experience, I will mention that the input end of the transmitting fiber has to be near and "pointed towards" the light source.  I believe the end should be shiny and rounded, so that the light gets "sucked up", rather than diffused before it even enters. So the point is to assemble all the ends of the fiber right in front of the LED.  When you have that figured out, then you have to kind of box it all up, so that all the "leftover light" doesn't light up the guts of your project like it's radioactive. 

At the output end, if you want the tip to glow, you need a rough surface--some sort of gentle sandpaper, I would think.  But if you want the end to output light instead of glowing, make shiny and rounded, as above.

Now, all of this is from someone who hasn't done ANYTHING with fiber optics.  But ya gotta start somewhere.

 

I recommend doing online searching.  The search "diy fiber optic projects" looked promising.

 

Ed

[gmpullman]

Hi,

I made this dispatcher's "Model Board" using fiber optic strands.

I bunched the fiber strands and applied just a bit of heat from a solderng iron tip, IIRC, not enough to flare the end but just enough to "polish" it.

I then used small (3 or 4 mm) heat shrink tubing to gang the strands, then applied a dab of Aleen's clear tacky glue (optional) to the tip of the LED and slid a piece of slightly larger, black heat shrink over this to make the "light assemblies" One TWO of the LEDs are a bi-color so I can make the board lights change color red-green or green-red.

 

I only needed a handful of colors but I'm sure you could bunch a larger number of strands until you get to about the diameter of the LED you are using. I think mine were 3mm. I'm sure you could make something work for Christmas or Holiday Lights. I bought assortments of fiber optic strands from the Ebay.

Good Luck, Ed

[gdelmoro]

Thanks for the replies. So I assume that if I cut a strand from a roll the end near the light needs to be smoothe. Do you touch the sand with the soldering iron or just hold it close enough to start it melting?

[RR_Mel]

gdelmoro

Thanks for the replies. So I assume that if I cut a strand from a roll the end near the light needs to be smoothe. Do you touch the sand with the soldering iron or just hold it close enough to start it melting?

 

I’ve done it both ways, it depends on the size of the fiber.  I can get a bigger blob using larger fiber without touching the fiber witch is probably normal.  I like the way ED attached the fiber to the LEDs, much better than the way I was doing it.  I was using a short piece of Styrene tube and clear Testors Cement.

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

[rrinker]

 I've also seen it done where you drill into the LED and insert the fibers into the hole - if you hold a water-clear type LED up to the light (regardless of actual color - these are the see through ones instead of the diffuse type) you can see the little cat-whisker wire connecting to the top of the actual semiconductor die inside. So long as you don;t drill down to this, the LED will be perfectly fine. For a couple of fine stands, this would work. For many more strands, you need to use a methood like above, because if you try to drill too big a hole it will just split the LED case.

The end that is at the light source should be polished for best light transfer.

Side note, I love that model board, I may have to try something like that. I can only imagine the comments that must get when a train rolls past and the lights on the panel inside the model tower actually change.

                            --Randy

 

[Geared Steam]

gmpullman

Hi,

I made this dispatcher's "Model Board" using fiber optic strands.

I bunched the fiber strands and applied just a bit of heat from a solderng iron tip, IIRC, not enough to flare the end but just enough to "polish" it.

I then used small (3 or 4 mm) heat shrink tubing to gang the strands, then applied a dab of Aleen's clear tacky glue (optional) to the tip of the LED and slid a piece of slightly larger, black heat shrink over this to make the "light assemblies" One of the LEDs is a bi-color so I can make the board lights change color.

 

I only needed a handful of colors but I'm sure you could bunch a larger number of strands until you get to about the diameter of the LED you are using. I think mine were 3mm. I'm sure you could make something work for Christmas or Holiday Lights. I bought assortments of fiber optic strands from the Ebay.

Good Luck, Ed

 

Ed, thats awesome modeling!! 

[gdelmoro]

cab I use Cyanoacrolate to glue the fibers together? Can i glue them in the holes?

[hon30critter]

gdelmoro

cab I use Cyanoacrolate to glue the fibers together? Can i glue them in the holes?

You can buy pre-assembled bundles on eBay and cut them down. You will be pretty well guaranteed even light levels from each strand. One thing to consider before buying is the size of the fibers. The minimum size from this source is .75 mm. You will need to determine whether or not that size will be flexible enough to fit where you want:

http://www.ebay.ca/itm/Fiber-Optic-Form-CHINLY-PMMA-Plastic-Optical-Fiber-Kit-for-LED-Fiber-Optic-Light-/262875467613?var=&hash=item3d34994f5d:m:migf7HlrD_OxXBfazGgB_og

Dave