I’d like to replace the dim old bulb in my yellow-box RS-1 with an LED. Here’s the bulb in the middle of the loco’s guts.
The bulb sits in the middle, and its beam (or rather dim glow) is transferred to the front and back headlights and number boards via these forked pieces of clear plastic. Regardez ici:
This setup is different from what the Roco-made F7 had. It was very clear what wires went where in that one. But I’m not sure what’s going on here. I don’t understand where I would attach the wire ends for an LED (with a resistor, of course). I can see the wires coming out from the bulb, but I don’t understand the logic of where they go and why. One seems to just get clamped down under the copper wire running front to back, and the other reaches over the edge but doesn’t really go anywhere in particular. The big metal plate doesn’t seem to have a negative or positive side.
I’d really like to ditch the forked plastic and mount an LED at each end. Does that look feasible? But I think first I will try to see if a single bright LED will maybe do the job. How would you go about this?
Please remember I’m not electrical very much. I know how to strip wire and I can solder, but amperage and ohmage… no clue. Diagrams drawn on the backs of gas receipts always welcome.
You could try one LED, but most I’ve seen are directional - they are focused towards the end/top of the bulb, so in this situation the brightest light would be shining sideways.
What I’ve done on some of these is trim the plastic light tube down to allow room for two bulbs, one each direction.
I’d advise using Evan Designs LEDs, you can get them from Walthers or other places. They are pricier than most LEDs, but come pre-wired with resistors and diodes so you can just connect the two wires to track power and the bulb won’t burn out - even on a 14V DCC layout.
First, I would strongly suggest using two warm white LEDs instead of just one. You will get much better results.
Second, is this locomotive going to be converted to DCC? If so, I would do that first. That will allow you to set the lights up for directional control.
You have probably figured most of this out already, but let me explain the wiring as it sits. It is very simple. You can see the black leads that come off of the trucks and supply power to the copper bus wires that run from one end of the grey board to the other. The light bulb leads are positioned under the bus bars to provide power to the bulb. The two copper strips that bend around the grey board supply power to the motor. One of those may be connected directly to the frame with the other one connected to one of the motor brushes (someone can probably confirm this). If you are converting to DCC you will have to re-wire the motor feed. You cannot use a live frame with DCC! If you are not going to convert the locomotive to DCC, then using the prewired LEDs suggested by a previous poster would be the easiest way to go.
There are a couple of options when it comes to getting better light out of the headlights and number boards. As I mentioned, using a single LED is not one of them:
The easiest effective solution would be to cut the light bars off leaving about 1" to 1 1/2" on each end where they go into the headlights. Then drill a suitably sized hole into the ends of the light bars so that the LEDs can fit right inside the light bars instead of just up against them. Use clear epoxy to glue the LEDs into the holes and try to make sure that the entire hole is filled. Then, cover the outsides of the light bars with silver paint, except for the lenses obviously. You want to use enough paint that the light doesn’t bleed through so it may require two or three coats. This will have the effect of forming a reflector so that instead of having light bleeding out everywhere, it will be redirec
I will add an alternate idea to Dave’s suggestion above in regards to affixing or mounting LEDs. While LEDs have much longer life spans than incandescents, they can and do burn out and epoxying them in place makes them VERY difficult (if not impossible) to remove.
It gives you working time to position the LED, dries clear, holds very well, and remains flexible once cured. And should you need to replace your LED(s) for any reason, they can be peeled off with steady pressure.
If you plan to ditch the light bars and mounting the LEDs directly to the headlight lenses, use a #32 drill bit and drill them by hand with a pin vise. A 3mm LED bulb generally has an OD of 0.113". A #32 drill bit will give you a 0.116" OD hole, which is a press fit for the 3mm LED. Therefore, no adhesive is needed to mount the LED to the headlight lens. Should the LED need replacing, a firm twist will loosen it from the hole. Should you still prefer an adhesive, I would again use the Testors Clear Parts Cement but a tiny amount.
If you plan to keep the light bars, I would agree with Stix and Dave that two LEDs would be recommended, as LEDs are much more directional than incandescents.
I generally take cut a piece of 1/8" metal tubing about 1/2" long and glue that in place where I want the LED or lightbulb to go. Then I wire up the bulb and slide it into the tube. That way, the light is better focused, and if I need to replace the bulb, I don’t need to unglue anything.
I’ve done something similar with 5/32" OD styrene tubing. I cut a piece 1/2" long and drill out 1/2 the length with the #32 drill bit. Once the tubing is glued in place, I paint the tubing black (to reduce bleed-through) and press-fit the 3mm LED inside the tubing. I used this method to add rear headlights in the cab of an old and a new Walthers SW1 switcher:
Stix, thanks for this warning and the recommendation. I don’t know from diodes, but I already have some LEDs with the resistors embedded. I’ll check out the Evans stuff.
Actually, I had not really figured all that out. It seemed like the bulb wires would want to be connecting to the copper buss wires, but the way they were routed and where they ended made me wonder if somehow the gray plate was conductive, even thought it seemed it could not be. In the Atlas F7 the plate was divided into left and right halves and the bulb wires were soldered directly to that. So that’s why I was confused here.
Not by me. Someday when I’m pushing up daisies maybe someone will want to rejigger it for DCC, but this is DC for now.
I believe I’ll start by cutting off some of the plastic light bars to widen the space where the existing bulb is, and try mounting two LEDs as you and others have suggested. If that doesn’t work, I can yard the light bar completely and try mounting them at the lenses.
Stix, I like the tube idea a lot. And Tom, thanks for the photo. That is extremely helpful for me.
[quote user=“tstage”]
If you plan to ditch the light bars and mounting the LEDs directly to the headlight lenses, use a #32 drill bit and drill them by hand with a pin vise. A 3mm LED bulb generally has an OD of 0.113". A #32 drill bit will give you a 0.116" OD hole, which is a press fit for the 3mm LED. [/quot
The light tubes have sections running to the number boards so, if the tubes are eliminated entirely, separate LEDs will have to be installed for each of the number boards. It is quite doable but it may be more complicated than Matt wants to get into at this stage of his working with LEDs. Having said that, I am a strong advocate for just diving right in! Do the clasification lights too! People will be impressed!
Tom, your suggestion about using Testors clear cement is excellent if you are securing LEDs in holes or tubes. The reason that I suggested using a quick setting epoxy was more related to attaching LEDs to the backs of number boards or classification lights where the LEDs will be just sitting against the back of the lenses. In cases like that, the faster the glue sets, the better because the LEDs have to be held in place by hand while the glue sets. At least, that is the way I have been doing it. Maybe someone has a better idea.
The Testors Clear Cement will hold just fine to the number boards, Dave. A thin strip of tape to hold it in place while it cures should do the trick. Once cured, you could use additional clear cement to reinforce it.
I recommend it over epoxy or CA because I don’t like the idea of permanently mounting something that could possibly need replacing. And if you do need to replace it, you’ll damage the part in the process.
The only time I use the Testors inside a hole is when I’m installing a 0603 LED in a brass locomotive headlamp. The Testors secures it inside the headlamp, as well as insulates the pads on the backside of the LED from shorting to the brass.
For the styrene tubing drilled out with a #32 drill bit, no adhesive is need at all. The fit of the LED inside the 0.116" OD hole is loose enough to press it in place and tight enough to hold it there.
You’re welcome, Matt. The headlight lenses I drilled out were on Stewart F-units and fairly thick so the drilled hole worked in that situation. If the lenses in your locomotive are <1/4", I would go with the tubing idea. And to secure the tubing inside the shell of your locomotive, I would use a liquid cement for the best bond.
When I converted all mine to DCC many moons ago, I cut my light tubes and polished the cut with a fine fingernail file. One LED on each end of the board with a resistor will give you directional lights.
Confirmed, the copper strip that comes up from the bottom of the motor that bends around the motor to lay on the top of the gray board and under the buss wire is not connected directly to the frame, so no live frame here on an ATLAS YB RS1.
Do you guys think since the OP is planning to stay with DC, maybe he could look for these Atlas printed curcuit boards #824-X001 at train shows or maybe hobby shops and get rid of the gray board with it’s ‘loose wire connections’ and do ‘hard wire’ connections. The tricky part is soldering wire leads to the copper strips that come from the motor brushes (needs heat sink and needs to be fast at soldering. Do not heat up the brush spring or the little plastic peg that holds the brush in place).
The OP would be able to solder LEDs with resistors to the correct PCB’s two inner solder pads on each end to get directional lighting. Many of us pulled these PCB’s from these engines when converting to DCC.
Just another option maybe.
There are no classifaction lights (body mounted lens) on the YB RS1, just number boards.
The picture below shows two Atlas RS 1 bodys,
The body in the top of the picture would have the gray board and one light bulb centered on that board to shine both ways at all times.
The body on the bottom would have the green PCB with a light bulb on both ends of the PCB. The clear light tube/runners have been shorten by ATLAS. With the two black diodes in the center of the PCB, ATLAS now gave your engine directional lighting.
“Ok. Important safety tip. Thanks Egon.” PC, this doesn’t sound like something I would venture to do. When it comes to soldering, I’m not that fast and I’m not that good. (Reminds me of a roommate I had that played guitar, and he always said, “I may be slow but I’m not very good.”) And this sounds like there could be serious repercussions to a botched operation. I am curious though… what do you see as the advantage to this dangerous mission? The idea of just soldering the bulb wired ends to the copper busses seems really appealing to me. What would be better about the hardwired green board enough to risk it?
Yes, soldering wires to those copper brush straps, if not done correctly, you will heat up the copper strap too much and then the brush springs will lose their expanded tension and relax and not keep their expanded tension on the brush, which will then not keep the brush snugg against the copper commutator pads on the armature shaft.
As with soldering bulb/LED w/resister wire ends to the buss wire that is good and easy. You could even slip the bulb/LED w/resister wire ends between the buss wires and the gray board, so no soldering for that.
What would be better with the hard wired green board???
diodes for directional lighting are already soldered in place.
bulbs on stiff/solid wires or the the LED w/resister with stiff legs/leds that
Only if the lightbar got cut right by the headlight. You could just cut the lightbars farther back towards the middle of the engine body and install the LEDs there. Then the light shines in the headlight and the numberboards. In the OP’s lower photo, the cut would be in the cab on the side towards the middle part of the engine body.
Right. I actually figured this out all by my little lonesome, and that’s where I planned to cut. I noticed that there are no numbers in the number board slots, though, so the light just piles out of those holes when the loco is running. I’ll have to put something in there.
But back to PC’s recommendations:
Ok, well let’s talk about directional lighting. I hear a lot about it and a lot of my locos have it, but I’m not sold. Do prototype engines really have their headlight turn off if they go into reverse? Obviously, if the engineer has swiveled his seat and is looking the other way there is no need to light the track that is now receding behind him, but wouldn’t it just be good safe practice to always have the lights on in both directions?
I recognize that a discussion of directionality is a departure from the quote unquote Topic, and I the undersigned, as the OP, being of sound mind, do hereby give my permission for any and all commentors to enlarge upon this departure without threat of recrimination or censure (by me, anyway). Have at it.
Directional lighting is great for running on the main line but only on the lead locomotive. Many RS locomotives ran long hood forward, but a few of them ran cab forward. Even fewer had dual controls. It wasn’t a matter of swiveling a seat around. The engineer would have to crane his neck around to see the brakeman’s signals.
Switching at night the locomotive would be running with either very dim headlight or just the numberboard, step lights, or side ditch lights on. The headlight shining brightly against a cut of cars would reflect so much light to impead the engineer from seeing the ground person. The rotary beacon would also be lit.
The bulb sits in the middle, and its beam (or rather dim glow) is transferred to the front and back headlights and number boards via these forked pieces of clear plastic. Regardez ici:
