Headlight Lenses/Light tubes?

[delamaize]

Hey everyone, As I mentioned in this thread: https://www.therailwire.net/forum/index.php?topic=60159.0 , I got a 3D printed C415 shell I am building into the Chehalis Western unit. I am taking a little artistic license, as I am lettering it for their late scheme, where this loco never wore that. Anyways, I have drilled out the headlights, then it dawned on me, I've never installed light tubes/lenses on any scratch build/kit bash I have ever done.

So here is the question, How do you guys go about doing light tubes/Lenses on diesels? I am at work, so I can't get any measurements, or pictures today. I am curious what you guys are using for material, and how you are going about it.

[fcnrwy23]

I have used, fiber optic cable.  For both headlights and rear markers (RED).
Depends on how much "Space" you have in that section of the body cavity.

The optic cable is held, against the face of the LED. With sections of shrink tubing.
I started with a large size to cover the LED, than progess down (in diameter size) to telescope until I had reached the size (diameter) of the optic cable..

Let me see, If I have any stock photos of this operation...

Jerry G.

[fcnrwy23]

The below example is what I could find on short notice...
It is for a RED LED with two cables.

Shrink tube large enough for LED, down to diameter of cable...



Jerry G.

[Bendtracker1]

Mike,
Here is what I did when I added LED's to my small fleet of U boats a while.
I removed the glazing (front only) and picked up some small fiber optics and inserted them in the two light tubes, glued them in place with a UV resin glue and then glued the LED right behind them.  I filled in the number boards with the glue, then painted and decaled them, they don't light up, but that's fine with me.
I think using the shrink tubing might be cleaner?

https://thelittlerockline.blogspot.com/2022/08/804-led-installation-in-u33bs.html

When I first looked into doing this,  someone on another forum said he had used the resin glue to fill the light tubes.
If you get the right stuff, the UV Resin glue is crystal clear.
This is what I wound using after trying the Bondic brand.  This stuff clings much better than Bondic.

https://tinyurl.com/bdfwjvhm

[craigolio1]

I find a piece of fibre optic that’s the same diameter as the hole. Bell the end by holding close, but not touching, a soldering iron. Cut it just a bit longer than the depth of the hole. Insert it from the inside. Then bell the end that stick out of the light. It naturally fills the hole and I’ve never melted a shell. Maybe practice on another piece of plastic. Then I glue an LED on the inside of the shell. Prior to that though I paint around where the LED will be with silver paint.

Craig

[x600]

Mike.

 i have a S#!tload of Fiber optic, come over and get you some. all different sizes and eleventy hundred feets rolls.

Greg O.

[randgust]

Considering the microscopic size of some of the LED's I've worked with, I question if you really want to fight with the fiber optics.

I was flummoxed to find wired LED's from CMR that fit inside a drilled styrene rod to get a working strobe on one of my Whitcomb projects.
https://www.cmrproducts.com/Pico-LEDs-1mm-x-0-5mm-Various-Colors-Qty-5-p131831345

That was the end of me struggling with fiber optics.  And I've been directly stuffing the bigger ones in headlights for years. 

The other approach (at least for dual-beam headlights) is to put the wired LED in a brass tube, insulate with CrystalCleer, and glue the tube up on the cab roof right behind the headlight.   Brilliant light, no cab leakage.

My basic issue with fiber optics is you'll never get that brilliant light; OK for accessory lights, but for the high-intensity stuff, direct LED is the first choice.

[_trainski]

Hey everyone, As I mentioned in this thread: https://www.therailwire.net/forum/index.php?topic=60159.0 , I got a 3D printed C415 shell I am building into the Chehalis Western unit. I am taking a little artistic license, as I am lettering it for their late scheme, where this loco never wore that. Anyways, I have drilled out the headlights, then it dawned on me, I've never installed light tubes/lenses on any scratch build/kit bash I have ever done.

So here is the question, How do you guys go about doing light tubes/Lenses on diesels? I am at work, so I can't get any measurements, or pictures today. I am curious what you guys are using for material, and how you are going about it.

I have been using 1.0mm plastic optical fiber (POF) for headlights. Measure the required depth, use a Revlon nail file buff to polish the lens, and use Norland UV 68 adhesive to attach EveModel 0402 or 0201 SMD LEDs — 2700 kelvin warm white. The light output is outrageous and I get no light spill after applying a bit of silver or chrome paint to any exposed areas. Also if the locomotive clear acrylic plastic headlight lens can accept it I’ll directly attach either a 2835 or 4014 SMD LED with the Norland UV adhesive to the backside and use AWG32/36 wire with pin header socket connectors for quick disconnects. So far it’s been a great way to improve headlights and get the colour temperature closer to the prototype. Cheers!

[Ed Kapuscinski]

I'm not going to say I do this "all the time", but I've done it a bunch recently. I've found that, as long as you've got a nice bright LED, just getting the fiber optic close usually suffices.

[delamaize]

I'm not going to say I do this "all the time", but I've done it a bunch recently. I've found that, as long as you've got a nice bright LED, just getting the fiber optic close usually suffices.

I'm using a TCS CN-GP decoder, because the mechanism is an older atlas RS3, once I got the decoder installed, I have actually found that this is the case. Greg (X600) is close to me, so I may go steal some Fiber from him and make some small lenses. I do have some other locos that could use the fiber optic treatment.

[peteski]

A bit of a warning: do not use CA glue with plastic optical fibers. It makes them brittle and they will break, especially under even a low stress.  At least that is my experience.  Epoxy does not pose any problems and most water-based glues (like canopy cement) will also be compatible.  Of course there might be multiple different types of plastics used for fiber optics and some might be CA safe. Just not in my experience.

[spr1955]

I had bought a Kato/Atlas RS-1 some time ago DC.  Put a DZ-123 in it. It did not have a rear light.  So about a month ago I bought a handful of 603's with prewired & resistors. There was enough room to put the 603 on top of the decoder (which is in the rear) after shortening the wires and reattaching the resistor. The shell just has a lens, that's all, but it did not need any more help as the 603 is pretty bright by itself, I pointed it to the rear lens.  Here is a picture of the rear light.

[wm3798]

Plastruct makes clear styrene rod in several diameters.  I use this to put lenses in my old Rivarossi steam.  A moment of heat to create a rounded lens, then poke it in.  As long as the light source is in the vicinity of the back of the rod, works like a champ.



Lee

[peaks]

I removed the glazing (front only) and picked up some small fiber optics and inserted them in the two light tubes, glued them in place with a UV resin glue and then glued the LED right behind them.  I filled in the number boards with the glue, then painted and decaled them, they don't light up, but that's fine with me.
I think using the shrink tubing might be cleaner?

https://thelittlerockline.blogspot.com/2022/08/804-led-installation-in-u33bs.html

Smart solution, Allen! What kind of black paint did you use? I find Vallejo Black Primer to provide very good coverage when dealing with lights.

[Bendtracker1]

Smart solution, Allen! What kind of black paint did you use? I find Vallejo Black Primer to provide very good coverage when dealing with lights.

Thanks.
A few of the very first ones I did I used the Black Vallejo, shortly afterwards, I used Floquil silver followed by Vallejo black.
I don't think I mentioned it in my blog, but don't forget to paint the shell with black and or silver as well.
The first one I did, the shell glowed a bit.