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gavino200

3D Printed LED light guides

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gavino200

https://multitron.co.uk/light-guides-light-pipes/

 

These look like they could be suitable for modeling purposes. Especially for modeling long fluorescent lights. Might be good for a subtle light effect when you want a light to be directly visible but don't want to stare directly into the light of  a tiny sun.

Edited by gavino200

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cteno4

Would need to be something like their m tube where the whole tube lights. Most of these are regular light pipe situations that delivers most of the light from one end of the pipe to the other and the tube itself doesn’t radiate much light. Other issue is it needs to be like 1mm or less in diameter for scale fluorescent tunes.

 

what might work is a long bit thin cross section that protrudes from a sealed box like a fluorescent tube (ilemlike a half round in cross section. And a leds in the box. Diffusing it to not have hot spots is the trick.

 

i tried way back to use just 1mm plastic fiber optic to see what you would see out the sides for like an isolated 10mm length and it wasn’t much of the light from the led as it’s made to transmit it down the fiber not out the sides! Needs something like their m tube that has something to deflect some of the light out the sides along the way. I’ve never played wirh using just plain acrylic rod as it’s not designed to pipe the light, but not sure if you would get the light needed to feel like a florescent tube.

 

sadly light does not scale literally so it’s tricky when modeling, just have to fiddle until something gives the right look of the prototype.

 

jeff

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gavino200

The one that I thought might work is the one on the top left in picture on this page.

 

https://multitron.co.uk/light-guides-light-pipes/custom-light-guide-solutions/

 

The fanned out wide end poking through a surface might look good as a fluorescent. I just read the "3D printing is the future" thread. I looks like there are a few people here with the necessary skill set for this kind of thing.

 

Could probably file something like that down to make it narrower. But it wouldn't necessarily have to be a single naked fluorescent tube, but rather a couple of tubes in a lighting cover. A long narrow light in any case.

Edited by gavino200

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cteno4

Yep, the first question is how well the light will diffuse out to the whole width. I assume wirh some distance that could be fanned out well. Second is how well the resulting light will act as a light source at scale looking like a florescent tube would. Third is getting the space for the behind the scenes stuff with the light source.

 

cool they can now 3d print light pipes with the proper optical properties. Perhaps something places like shapeways will offer!

 

cool stuff and always great to keep looking at things from other areas to see how they could be used in our modeling. I think our local craft and dollar store thinks imma shoplifter as I will walk up and low the isles just looking at items as possible model or tool use! 

 

that page made me remember if do have some little rectangular panel light pipes like those in the middle right that are like 1x6mm in profile and about 10mm Long somewhere that I scavanged a pile from something way back. I’ll go dig.

 

florescent lights are something that would be really nice to have. Inobus approach with a diffusion Block on an smd led is pretty good as we rarely see our model florescent light figures directly as we would at angles in real life.

 

there are some long thin leds that are used for side lighting panels, but they are a bit big (and built to be very bright) but could be used as a whole florescent fixture box and diffuser.

 

EL wire is sadly too big for n scale use and cranky and my ears hear the bloody high frequency transformers whine!

 

just occurred to me that large lit sign letters could be done easily with 3D printing by printing the opaque wall with the letter holes then printing the letters to fit in those holes in frosted translucent  plastic and fit I holes and back with the desired color gel film and led light. Once multicolored translucent 3d materials are out there you could do a multicolored jigsaw puzzle light. Even print a walled baffle behind it to have different parts light up in sequence, etc.

 

jeff

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gavino200

That's funny about the shoplifting. Interesting idea about lighted signs. I'd like to try that.

 

You may have guessed, I'm thinking about this for my nutty tunnel project. I want the lights for atmosphere, but I don't actually want much illumination. The tunnel will already be somewhat bright on account of being open on one side. Also, space is not an issue. The light pipes can be buried in foam.

 

http://www.allrefer.com/worlds-longest-underwater-tunnel

 

Perhaps Kabutoni could help with this.

Edited by gavino200

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inobu

Here we go again...... you talking about something I'm doing as well. I been harping on light control and diffusion. 

Had one project where a guy wanted period lighting in his HO DoodleBug. Its a early 1900 passenger train and I just finished it up.

 

medium.IMG_2395.JPG.c7fc550b190b1acc7a22

 

large.IMG_2390.JPG.5632845b5389b8356b09b

 

This is done by 6 warm 1210 LED's using fiber optics. Those LED strips are too much for our scale requirements. Too many lumnes

which works back to wattage heat that is was wining about. 

 

You can see how I control the lighting beams with the fiber optics and create miniature bulbs which cast realistic light beams.

 

I going to start on florescent lights for the platform like I stated on the other thread. It going to take both diffusion and beam control 

to pull it off.

 

Its all about light control. The platform floors also plays a part.

 

Inobu

 

Also I used decoder so it has 6 section lighting. Theres 4 bathroom lights and 8 compartmental lights which can be switch on and off. 

 

I forgot the main point of my reply.

 

The 3D print will not allow enough light to pass through and radiate like a real florescent light. This is where the diffusion will have to take over and

using water clear plastic to channel the light into the diffusion. Finding the right combination will be a challenge.  .   

 

 

 

 

 

 

 

 

 

Edited by inobu
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cteno4

Inobu,

 

great work! Tuning down the leds and using the fiber optics to make bulbs really does a nice job of a realistic light source! 

 

This is the big problem with scale lighting in that it’s a lot ow work to tune the light sources down to the level of prototype light sources throw and also the number of them. Love to see what you do with the florescent bulbs.

 

jeff

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Kiha66

What a great idea!  I've ordered some 2mm side emitting fiber optic cable, which hopefully will mimic the glow of a CFL.  I'll post results when it arrives.

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gavino200
12 hours ago, inobu said:

 

 

The 3D print will not allow enough light to pass through and radiate like a real florescent light. This is where the diffusion will have to take over and

using water clear plastic to channel the light into the diffusion.

 

 

 

 

 

 

 

 

 

Yes, funny how that turns out. But lucky for me.

 

Can you expand on the above statement a little for me. Mainly the "water clear plastic". I'm afraid you'll have to ELIF ("Explain like I'm five") a bit.

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inobu

The light need crystal clear plastic to propagate. The plastic use is typically crystal clear like water hence the term. It needs to be bubble free as well or the light beam will hit the bubbles and disperse

 

3D printing is a layering process which creates a cloudy translucent finish.

 

The lens in your example is made from water clear plastic.

 

Inobu

 

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cteno4

Gavin,

 

most optical fiber is made in a way that channel the light waves to keep going on down the fiber and not (as little as possible) radiate out the sides of the fiber as the goal is to get as much of the light from one end to the other. How the glass or plastic is made and it being very clear is the trick. Any little occlusions like bubbles, fissures in the crystal or polymer structure, or particles will be obstructions to the light waves and reflect some out the sides of the fiber to make it glow more.

 

side emitting fiber optic cable is fibers that have tiny occlisions that bounce some of the light out the side of the fiber and make it glow along the sides of the fiber more so the whole fiber glows. Of course with distance this will change as more of the light is reflected out of the fiber the further you go.

 

jeff

 

 

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gavino200
25 minutes ago, inobu said:

The light need crystal clear plastic to propagate. The plastic use is typically crystal clear like water hence the term. It needs to be bubble free as well or the light beam will hit the bubbles and disperse

 

3D printing is a layering process which creates a cloudy translucent finish.

 

The lens in your example is made from water clear plastic.

 

Inobu

 

 

If I tried to "whittle" one out of a block of this crystal clear plastic. Or more likely, modify an available light guide, would I be able to polish the surface sufficiently for appropriate light emission?

 

Edit: Ok, I get what you're saying about radiation. The M-CUT 2D-Light Guide Systems on page four of the catalog, would be the right shape, but they're designed to pipe light directly out in a straight line, rather than radiating light out in all directions to light of a room or section of tunnel. 

 

How about if the surface was slightly roughened to give a sort of 'ground glass' appearance? Better radiation?

Edited by gavino200

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gavino200
7 minutes ago, cteno4 said:

Gavin,

 

most optical fiber is made in a way that channel the light waves to keep going on down the fiber and not (as little as possible) radiate out the sides of the fiber as the goal is to get as much of the light from one end to the other. How the glass or plastic is made and it being very clear is the trick. Any little occlusions like bubbles, fissures in the crystal or polymer structure, or particles will be obstructions to the light waves and reflect some out the sides of the fiber to make it glow more.

 

side emitting fiber optic cable is fibers that have tiny occlisions that bounce some of the light out the side of the fiber and make it glow along the sides of the fiber more so the whole fiber glows. Of course with distance this will change as more of the light is reflected out of the fiber the further you go.

 

jeff

 

 

 

Thanks. Its coming back to me. I remember this from physics. The fiber optic cable has a thin coating of a glass with a different refractive index to make it difficult for a critical angle to be reached. I'd bet these plastic light pipes, just rely on geometry.

 

As far as I can see, side emitters would only work if they were recessed. Otherwise you'd either see curvature where they jut out, thereby ruining the illusion. No?

Edited by gavino200

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cteno4

Gavin,

 

yep they do that in both plastic and glass along with how the fiber is spun to get maximum transmission with the least dispursionn or reflection.

 

yep you would want the final surface to be roughed up to allow diffusion and make it glow and not be a beam coming straight out that a polished surface would give you. This is the diffusion that preaches inobu does.

 

thinking about your lottle florescent tunnel fixtures I bet a 3d printed frosted that’s like 2mm x8-10mm in cross section and rounded like those fixtures (sort of like a D in cross section)may work with an smd behind it. Question is will it diffuse to the ends well enough. I’ll try to play with some 3d printed frosted detail part sprues I have and see how well they diffuse the led. Even clear haldround plastic with the surface totally frosted by sanding or sandblasting may work.

 

othe issue might be cutting the slots inthe tunnel wall for them, but maybe the housing/diffuser could just be glued on the inside of the tunnel and a hole drilled thru the wall to the center of the fixture for the led to go in, but again the question is will it diffuse well like this out to the ends. Good thing is these would be turned way down in brightness and thus diffusion have more of an effect and not be overwhelmed by the direct transmission straight thru in the center from the mini sun.

 

using side emitting fiber might work back lit. It would look more like a round tube fixture than the sort of half round and may be harder to seal the backlighting in. End lighting them would just not work. I’ve only seen the side emitting fibers down to like 2mm usually and that 1’ in diameter scale so quite big and why I’ve never tried it with trains.

 

something to just fiddle with and see if you can get the right effect. Also you will need to mock up a section of tunnel out of cardboard and styrene to test this in as the effect will change under the low light conditions and also change as you add more. Scaling down lighting like this is tricky and just requires experimenting a lot to get the effect you are looking for. Also this effect may only show up under certain light conditions in the room and can get washed out in others.

 

plastic fiber optics (don’t bother playing with the glass as it’s hard to cut and polish and small bits from cutting can be nasty skin irritants) are fun to play with. They make great light bulbs like inobu’s example. I’ve pancaked the ends with some heat then put a 3mm sequins behind it as a lamp shade to make old style overhead lamps over doors and in larger building spaces (tricked out my old atlas round house like this when I was a kit using one of those kitschy 70s fiber optic lamps). There are lots of cheapo toys and such on ebay for a buck that have a little bundle of fiberoptic strands with ends polished or melted to have little glow effect and even come wirh a little led. These are not high quality fibers but fine to move light a couple of inches from an led source and play with. You can get spools of better quality plastic fiber as well and then play with the ends to get different effects. You can bend them pretty well wirh some heat but tight bends loose light fast.

 

Cheers,

 

jeff

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gavino200

FYI - I emailed the company. Minimum order quantity is 300 pieces. The unit cost is roughly 2 pounds Sterling. Bummer.

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cteno4

yeah its a custom type of printing so not shapeways!

 

frosted detail 3d print may diffuse well, at least a lot cheaper way to test!

 

jeff

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gavino200
5 hours ago, cteno4 said:

yeah its a custom type of printing so not shapeways!

 

frosted detail 3d print may diffuse well, at least a lot cheaper way to test!

 

jeff

 

I'm willing to give it a shot. Do you have a vendor/material in mind?

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gavino200

The design and general shape of these guides is close to ideal. There's a nice write-up on materials. They're using PMMA. One of the few plastic materials I have experience with. I use this stuff at work to make a quick drying cement.

 

These guys have no minimum quantity order. They'll give me a price quote if I send them a rough sketch. I'll let you know.

 

http://www.eljentechnology.com/products/light-guides-and-acrylic-plastic

 

This is a step in the right direction. No dimensions, but given the product, it's likely too small. But right quantity and price range. 

 

https://www.aliexpress.com/item/Dower-Me-Charging-Indicator-Light-Guide-Plate-For-Sony-Xperia-Z5-Premium-E6883-E6853-E6833-Z5P/32840392115.html?spm=2114.search0204.3.17.32MtMW&ws_ab_test=searchweb0_0,searchweb201602_4_10320_10152_10321_10065_5000015_10151_10344_10068_10345_10342_10547_10325_10343_10546_51102_10340_10341_10548_10194_5130015_10541_10084_10083_10304_10307_10539_10180_5080015_10312_10059_10313_10314_10184_10534_100031_10604_10603_10103_10605_10186_10594_5060015_10596_10142_10107,searchweb201603_14,ppcSwitch_4_ppcChannel&algo_expid=3b2e91e9-8f89-44f3-9d31-04186c71ba44-2&algo_pvid=3b2e91e9-8f89-44f3-9d31-04186c71ba44&rmStoreLevelAB=0

 

 

Edited by gavino200

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gavino200

I was lighting some trains last night when it hit me that I should be able to get this effect by cutting down some Kato lighting kit diffusion inserts and sculpting them to fit my needs. I could simply fix an LED behind the plastic. 

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