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Topic: making optical fibers/EL wires sturdy? (Read 762 times) previous topic - next topic

jantran

Jul 06, 2015, 08:08 pm Last Edit: Aug 14, 2015, 09:16 am by jantran
I'm sorry if this isn't the place to post this.
But I had the idea of making a figurine from optical fibers and control the colors with an Arduino.
Before getting into the technical part, what can I use to make the opitcal fibers sturdy? I'm thinking of putting them inside some kind of tube and/or covering them inside some kind of hardening translucent material. I'm sure someone can think of a better idea.

Inspirations:
http://i.imgur.com/J9PuPn7.png

http://i.imgur.com/J8Puxn7.png

Riva

Not much help on your question but have you seen/used EL wire
The problem with fibre optic cable is you mostly just get a light out of the end of the cable and don't see it while its travelling down the cable.
Don't PM me for help as I will ignore it.

jantran

#2
Jul 07, 2015, 10:31 am Last Edit: Aug 14, 2015, 09:17 am by jantran
Thanks for the suggestion. Its normal that fiber optics have more light coming out from the end than any other place, the inside is after all a reflector meant to make the light travel through it, its just not 100% reflective of course and some light bleeds out, which is a good thing because otherwise most of the light would come out before it would travel few inches. I dont think its true that light doesnt come out while its traveling through the cable though. Maybe in some types it doesnt or it does but the outer shells arent translucent to see it.
Maybe this is one of the rare cases where buying cheap, less efficient stuff is actually better.
https://www.youtube.com/watch?v=lijy2n_kvlw

https://www.youtube.com/watch?v=161j4arzZpg

Whichever Illl be using though, fiber optics or EL wires, Illl need to make it sturdy somehow.

I'm thinking of some transparent tube that can be deformed as you wish but hardens after being exposed to heat, UV light, or something. Or maybe some translucent gel that needs time to harden and wont give a rough. bumpy texture.

Riva

Thanks for the suggestion. Its normal that fiber optics have more light coming out from the end than any other place, the inside is after all a reflector meant to make the light travel through it, its just not 100% reflective of course and some light bleeds out, which is a good thing because otherwise most of the light would come out before it would travel few inches. I dont think its true that light doesnt come out while its traveling through the cable though. Maybe in some types it doesnt or it does but the outer shells arent translucent to see it.
True that not all the light is trapped in the fibre for it's entire length but the links you posted are for a specially made type of fibre from Corning that is designed to emit light from the sides.
Maybe something like the plastic brim wire here would do the job better as it's not designed to be so optically pure.
Other possibilities...
http://botnexus.com/t-glase-3d-printing-filament-explained/
http://www.hobbylinc.com/htm/pls/pls90291.htm
http://www.amazon.com/Plastruct-Ar-2h-Clear-Rod-Pls90291/dp/B0006O6QXU
Fly fishing line.
or as a last resort using normal cheap fibre optic cable and rough the outside with fine sand paper.

For small structures EL wire should support it's own weight and maybe the acrylic rod would also self support for small structures.
Don't PM me for help as I will ignore it.

jantran

#4
Jul 07, 2015, 04:16 pm Last Edit: Jul 07, 2015, 05:14 pm by jantran
I'm not sure if EL wire won't be quite flexible, even if it will support its own structure.
But that acrylic tubes look very promising!
Question is how I can bend them just the way I need while heated, and not damage the EL wire or fiber optic inside it in the process (unless there's a heat resistant wire that comes to your mind which I could pass through the acrylic tube instead and tie it to the tip of the fiber/wire, then just pull the fiber/wire inside the tube by pulling the heat resistant wire).

Also, are there thinner than 2 cm diameter ones you could find? 2 cm diameter is pretty thick for what I'm working on, if 2 cm was the thickness I was after I guess even neon tubes could work. 5mm-1cm would be great.

Also, what if the tubes are shorter than I need? Are there any tricks for creating seamless acrylic connections?

Quote
or as a last resort using normal cheap fibre optic cable and rough the outside with fine sand paper.
I didn't understand what this suggestion was for.

Riva

eBay seem to do 1.3mm EL wire.
It normally has a solid core wire so should bend to shape (without heat) and stay but there is a limit to length/size before it cannot support it's own weight. EL wire/sheet glows when connected to a suitable power source and does not need a light shining down the end.

Using acrylic wire I would expect a gentle heating at the bend point, bending and cooling would get it to take on and hold the shape you need. I don't know how you would seamlessly (and invisibly) joint them together though.

Quote
I didn't understand what this suggestion was for.
Because a normal fibre optic cable does/should not leak much light through it's walls if you rough the walls with sandpaper they are more likely to leak light through them maybe giving them more of a glow. The fibre cable would need to be the type that bounces light off the inner walls instead of the type that uses different fibre properties though it's cross section to keep the light in the centre of the core.
The reason for suggesting this is our old xmas tree with fibre optic cables in had the ends roughed up for the last few centimetres so you could see the light (see attached image)
Don't PM me for help as I will ignore it.

jantran

#6
Jul 07, 2015, 09:35 pm Last Edit: Jul 07, 2015, 09:35 pm by jantran
I see.

So the two good options till now seemed optical fibers inside acrylic tubes for sturdiness or EL wires inside acrylic tubes for the same reason.
But someone else mentioned using acrylic rods without anything and just heating and bending that. While that will look visually better and easier to set up, I'm not sure how how well the light travels through those and how much bends affect light transference. I can't find any info on this on the internet.
https://www.youtube.com/watch?v=uP1OCr6cD1M

Anyone familiar with these?

dannable

Why don't you get some and try it? Clear plastic has been used to conduct light for years so I can't imagine that you'll be disappointed, and you will find out how easy it is to manipulate.
Beginners guide to using the Seeedstudio SIM900 GPRS/GSM Shield

jantran

Shipping time.

If there were at least some youtube videos I'd risk the wait. But there's only a handful that don't give any idea about the dim rate and no video for bent rods.
https://www.youtube.com/results?search_query=acrylic+rod+light&page=1

sonyhome

on ebay look for side glow fiber optics. however the light will be dim/etheral, and you'll need a bright led at the ends to make it glow.


EL wire will be much brighter, and is flexible and easy to play with. it is fragile so it'll break if you flex it too much like on a worn fabric, after someuse. most damage comes where it is soldered to wires, but  that's easy to fix. some breakage can happen when the  el itself breaks and you can end up with dark sections or weird blobs of on vs off sections.

you can buy el from 1.6mm to 5mm (1/2cm). different colors will have different brightness because of tech. lime green is brightest.

it's very cheap on ebay, unless you need super bright 3rd gen el.

for a sculpture el is likely good.

you could also make your sculpture in acrylic, and just put leds on the sides or bottom to have it glow. No need for fiber optics, unless you want to use it to distribute the lights.

have fun!

Chagrin

If there were at least some youtube videos I'd risk the wait. But there's only a handful that don't give any idea about the dim rate and no video for bent rods.
You're looking for "light pipe design" (google that for tips). But if you're looking for the general rule of thumb, light will reflect back inside an acrylic rod, and similar clear plastics, for any angle less than 42o. This assumes a perfectly smooth surface finish of course, or in your case you'd be controlling how much light emits from the side by controlling that surface finish -- making it rougher where you want more light.


jantran

Interesting. What does 42 degrees mean though? I can bend a rod 179 degrees by having a tiny curve where it bends or have a very smooth bend along the whole rod so the rod takes a circle shape.

With EL wires I could put it inside an acrylic tube and sand the tube because I don't want the wires to be visible.
With acrylic rods plus leds it would look different, more transparent but I don't know if I could make the light travels across all the bends.

sonyhome

the el isnt transparent, but it looks like one glow tube.

i suggest spending 10 bucks on ebay to get a strand and play with it. same with optical fiber. it's not super expensive and is a small cost vs your final project. also you'll find other ways to use them later.

for the side glow i bought some, and stretched it to make whiskers, it's not quite perfect but it's not bad.

Chagrin

Interesting. What does 42 degrees mean though? I can bend a rod 179 degrees by having a tiny curve where it bends or have a very smooth bend along the whole rod so the rod takes a circle shape.
Imagine the solid rod as a tube and a little ball bouncing off the walls as it travels down the tube. If the ball hits any wall at a > 42o angle it will escape the tube.

So yes, if you do a sweeping bend then the light will continue to travel down the rod.

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