Today, I am going to install LEDs in my Proto 2000 PAs.
These are the standard dome shaped LEDs with the rounded tops.
They mount on a clear plastic housing on the chassis and then the shell fits over them.
So, the question is, what is the best way to prevent lighting leaks.
Do you paint the sides black?
Do you put heat shrink tubing over the sides leaving the top exposed?
I am interested in what works for you.
Rich
I have done it both ways - depends on the model and how the lights are laid out!
I also use the Tower LEDs (Minitronics) which with a little reaming will fit right into the Headlight housing of most models!
I was able to solder 2 of the Tower LEDs together (one above/beside the other) and this arrangement would slide right into the typical double headlight in an engine shell.
Some require that I file the lenght of the Tower LED light pipe off a bit - others it is the right length!
Just needs to be tested out when trying to fit them in.
BOB H - Clarion, PA
I have used both way’s also. Depends on the application and how much room you have. I have painted some Silver first then Black. In buildings where I use 5mm Led’s, I sand around the whole LED to let more light out. Test before you install and see what way you like and what works to your eye.
Take Care!
Frank
Whatever works is my approach. Paint is sometimes the best, because it’s thin. Another similar thing is black liquid electrical tape, which is thicker, but tends to block light better in a lot of cases.
Black shrink tubing is very effective, but also somewhat thick. It is neat and easy to apply, so tends to be what I prefer. It also adds some mechanical integrity to the LED/wire assembly to hold it in place.
In any case, I still need to do something more with my PA, as it has a light leak. The LED and wiring have black shrink on them, but I left enough light escaping to be more visible than I like. I’m thinking an application liquid tape to the underside of the light tubing might do the trick.
Thanks, guys.
Is the objective to darken everything but the tip of the LED?
Rich
Yes, but always best to do so with the minimum material necessary. Oftentimes, as with the PA, it also needs to clear the front truck’s top end where it swivels.
BTW, forgot the biggest advantage of the black liquid electrical tape is that its spans gaps, which paint has a hard time doing.
Thanks, Mike, I am hopeful that the clear plastic housing on which the bulbs were mounted will be suitable for mounting the LEDs the same way. In that case, I shouldn’t have any problem with clearance from that front truck assembly.
Rich
I put a piece of black heat shrink tubing over the LED.
That is what I am considering.
Rich
If these are the 3MM LED’s. I use heat shrink. I use a size that is smaller the the LED and streach the shrik untill it will fit over the LED. Then cut to a lenth that will just let the tip of the LED show. Then hit with a heat gun. This makes the shrink very thin and keeps the light pointing forward only.
The Mars light is going to be a 5mm LED and the headlight below the Mars will be a 3 mm LED.
Rich
Subway cars of LION have LED’s near the top of the car and light conducting plastic to deliver the luminesence to the bottom of the car where the headlamps are.
LION removed entire circuit board provided by manufacturer. Him mounted a BRIGHT RED LED in place of the original LED, and then two bright white LEDs on either side of that. White lights forward, red lamps on the tail. Just what you would expect.
To prevent light leakage, him, (the smart LION) used kid’s modeling clay to hold the assembly to the roof of the car, and to block unwanted light leakage. Animals with more patience that a LION might do a better job of it, but good enough is good enough while purrfect tends to upset the larger variety of felids.
ROAR
Oh yeah!
I installed the LED lighting today in one of the two PA locos.
The whole thing went pretty smoothly.
I used heat shrink tubing to provide the hoods to prevent light leaks.
Rich
Excellent![tup]
This turned out to be one of my neater installs, probably because there’s plenty of elbow room inside the big ol’ PA carbody.
Use this as a guide- when you have the room, default to heat shrink tubing as a rear/side light block; when clearances are tight, use flat black paint- two coats, if possible, but thinly applied. Avoid electrical tape- it rarely sticks well in small applications, and if stretched, will come loose soon after applying.
Cedarwoodron
One final question on light leaks.
I notice slight leak visible under the front of the loco.
I assume that is because of the fact that I left the tip of LED uncovered.
So, my question is, should the head shrinh tubing extend beyond the tip of the LED?
Rich
Whatever works…it sure is not going to hurt anything.
It would be just like a fiber optic light. I did it on ditch lights.
Frank
Yes, this will work, but do your best not to let the heat hit that end of the shrink or it will “pinch down” and obscure part of the face of the LED. Keep the heat toward the back of things so it gets a good grip so it doesn’t move and leave it at that for best results.
Thanks, Mike, that’s what I wound up doing.
The real trick on these PAs is to get both lights centered in front of their respective housings and lenses.
The Mars light is no problem, but the headlight tends to sit too low relative to its housing and lens.
I recall it being that way as well with the incandescents.
Rich