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.
Thanks,
-Matt
Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.
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.
https://www.walthers.com/led-5mm-7-19v-universal-ac-dc-dcc-pkg-5-warm-white-266-u50
Hi Matt,
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 redirected towards the lenses.
The more complex solution would be to eliminate the light bars almost entirely by cutting off the lenses and tossing the light bars into your spare parts box. Then, mount an LED behind each of the headlights and number boards. This will give you brilliant headlights but you might want to install a second resistor (10,000 ohms?) for each of the number boards so they are not as bright. Note that you will want to paint the inside of the shell black around each of the lights or the shell may glow in the dark.
If you are using DCC and you really want to get fancy, you could add in classification lighting using RGB 0608 LEDs. It sounds harder than it actually is.
I will add a couple of final notes regarding the use of epoxy glue. First, get the fastest setting glue that you can, i.e. 90 seconds. Five minute epoxy will take forever to hold the LEDs firmly in place. Second, have the LEDs lit when you are positioning them against a flat surface. The LEDs will want to shift around before the epoxy sets and the slightest misalignment will ruin the effect. Hold them in place for a few minutes even after the epoxy seems to have set. The epoxy can still 'flow' slightly even when it feels firm. I use a separate 12 volt power supply with a suitable resistor to temporarily light the LEDs while I am working with them.
Sorry about the long winded response!
Cheers!!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Matt,
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.
When it comes to lighting, I would recommend Testors Clear Parts Cement (PN 3515 or 281217) over any epoxy.
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.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
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.
Stix,
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:
Wow, thanks guys. Lotsa great info here.
wjstixYou 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.
hon30critterYou have probably figured most of this out already, but let me explain the wiring as it sits. It is very simple. You can see
hon30critterSecond, is this locomotive going to be converted to DCC?
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.
tstageIf 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.
Thanks all, when I get my courage up to try this I'll let you know how it works out.
Hi Matt, Tom and Stix,
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.
crossthedog 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. This is also great detailed info, thank you. I'll have to look at the lenses. I didn't know there was enough "length" in them to actually drill a hole into. I thought they were pretty tiny.
This is also great detailed info, thank you. I'll have to look at the lenses. I didn't know there was enough "length" in them to actually drill a hole into. I thought they were pretty tiny.
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.
Hi Tom,
I have some Testors Clear Cement. I'll give it a try the next time I am installing LEDs. Thanks for bringing me up to speed.
Haven't seen one of those in a long time.
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.
Pete.
wrench567I 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.
hon30critter Hi Matt, 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. Cheers!! Dave
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.
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.
PC101The 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).
crossthedog PC101 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). "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? -Matt
PC101 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).
"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???
1) diodes for directional lighting are already soldered in place.
2) bulbs on stiff/solid wires or the the LED w/resister with stiff legs/leds that you want to use would be soldered to the end of the green board and formed/bent to mate up with the clear light rods/tubes.
I am still running ATLAS YB locos. in DC with gray boards and one light bulb and some have with the green PCB board and directional lighting with bulbs and some with a green board with a 8 pin FM DCC ready socket with an 8 pin M plug. After that it went to a DCC decoder w/8 pin M end then to DCC only decoder board then to a DCC decoder board w/sound. I an not sure at this time which ones have bulbs or LEDs.
In the August 2023 M R magazine, Editor Eric White talks about tinkerers and mad scientists. How true that is.
hon30critterThe 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.
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.
wjstix hon30critter 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.
hon30critter 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.
But back to PC's recommendations:
PC101What would be better with the hard wired green board??? 1) diodes for directional lighting are already soldered in place.
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.
Oh, hey I almost forgot:
wjstixI'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.
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.
crossthedog 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?
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?
With DC you only have two options: Both headlights always on, or directional.
It's whatever looks best to you while you're running trains.
crossthedogI 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.
A couple of companies make decals of numberboards, check Walthers website.
crossthedogOk, 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?
No they don't. The engineer controls which headlight is on or off, bright or dim. I believe when switching like in a yard, the engine has to have both lights on (at least dim?) for safety reasons.
Since the Atlas engine you have doesn't have a lightboard, both headlights will be on anytime there is power going to the engine (off when stopped) unless you add diodes in the wiring circuit for each light to make them directional.
Thanks for the tip about number board decals.
wjstixSince the Atlas engine you have doesn't have a lightboard, both headlights will be on anytime there is power going to the engine (off when stopped) unless you add diodes in the wiring circuit for each light to make them directional.
EDIT: Actually, it looks like PC101's image upthread shows a nesting pair of them in the center of the green lightboard. They look just like resistors to me.
crossthedog Thanks for the tip about number board decals. wjstix Since the Atlas engine you have doesn't have a lightboard, both headlights will be on anytime there is power going to the engine (off when stopped) unless you add diodes in the wiring circuit for each light to make them directional. Hmm. I don't mind the nondirectionality. But I would love it if the headlight could stay on bright even when the locomotive was running very slowly or stopped. Can this be achieved through diodes? What do diodes look like, and what kind of bait do you use to catch one? EDIT: Actually, it looks like PC101's image upthread shows a couple of them in the center of the green lightboard. They look just like resistors to me.
wjstix Since the Atlas engine you have doesn't have a lightboard, both headlights will be on anytime there is power going to the engine (off when stopped) unless you add diodes in the wiring circuit for each light to make them directional.
Hmm. I don't mind the nondirectionality. But I would love it if the headlight could stay on bright even when the locomotive was running very slowly or stopped. Can this be achieved through diodes? What do diodes look like, and what kind of bait do you use to catch one?
EDIT: Actually, it looks like PC101's image upthread shows a couple of them in the center of the green lightboard. They look just like resistors to me.
Diodes simply allow current to pass in a single direction only. That's why a single color LED only lights at one polarity.
EDIT to add: A diode does cause voltage drop, so it would be possible to wire diodes in series to reduce the light brightness. Or just use a resistor.
To have the lights on while the locomotive is stopped normally requires a battery.
I suppose you could design a lighting circuit to provide regulated voltage for the LEDs, and another circuit to prevent the motor from turning until track voltage got above the regulated voltage. That would allow lights to be on while the locomotive is stopped, although the track is still powered.
AEP528I suppose you could design a lighting circuit to provide regulated voltage for the LEDs, and another circuit to prevent the motor from turning until track voltage got above the regulated voltage. That would allow lights to be on while the locomotive is stopped, although the track is still powered.
I thought I'd report on progress. I cut the long hood light bar, drilled a hole in it, the edges of the hole broke, I put an Evans 3mm LED in the hole and taped it so that it would hold together, reinstalled the shortened light bar and loosely wrapped the LED wires around the buss wires, then closed up the hood to test it.
Success! Here's a quick video of the RS-1 with the new headlight:
https://drive.google.com/file/d/1lcdHsMsXXQ0bGkt8iQ75HbSphYb70GWT/
Here' the project so far:
I need to cut and drill the other light bar and wire up the other light, and then I guess solder the wire ends to the buss wires. But it seems to work and it's nice and bright. That's all I wanted.
Thanks everyone for all the help.
crossthedog AEP528 I suppose you could design a lighting circuit to provide regulated voltage for the LEDs, and another circuit to prevent the motor from turning until track voltage got above the regulated voltage. That would allow lights to be on while the locomotive is stopped, although the track is still powered. That would absolutely smash. I love that idea, but I'm not even going to ask you how to do it.
AEP528
That would absolutely smash. I love that idea, but I'm not even going to ask you how to do it.
FWIW one of the original purposes of the green 'lightboard' use in engines was to provide what was called 'constant lighting'. The board would be wired so that when track power was applied, the first couple of volts were routed directly to the headlight, and then as you increased power it would get to the motor to move the engine. This meant if you were careful, you could reduce the throttle enough to make the engine stop, but keep a trickle of power in the track to keep the light on. (The lightboards were also usually set up to do directional lighting so only one bulb was on at a time, depending on track polarity.) Unfortunately, this did mean that if you had some engines with lightboards and some without, the ones without would start sooner and run a bit faster then those with the lightboards, so it make it harder to run multiple engine consists.
With DCC, you press a button to turn the lights on or off whether running or stopped, so it makes it a lot easier. It's programmed into the decoder in the factory.
wjstix FWIW one of the original purposes of the green 'lightboard' use in engines was to provide what was called 'constant lighting'. The board would be wired so that when track power was applied, the first couple of volts were routed directly to the headlight, and then as you increased power it would get to the motor to move the engine. This meant if you were careful, you could reduce the throttle enough to make the engine stop, but keep a trickle of power in the track to keep the light on.
I might keep an eye out for those green boards and if I get a couple of them I could put them in several engines that would make a good mu consist.
crossthedogI cut the long hood light bar, drilled a hole in it, the edges of the hole broke,
You can reduce the amount of breakage by starting with a smaller drill bit, i.e. 1/16" and then enlarging the hole incrementally until you get it to the desired 1/8".
The light looks great. I would suggest painting the light tubes if there is light shining out of the bottom of the locomotive.
hon30critterYou can reduce the amount of breakage by starting with a smaller drill bit, i.e. 1/16" and then enlarging the hole incrementally until you get it to the desired 1/8".
hon30critterThe light looks great. I would suggest painting the light tubes if there is light shining out of the bottom of the locomotive.