The headlight that comes with the HO Bachmann consolidation burns very dimly. It looks like it is a grain light bulb. I would like to replace it with a brighter LED. To do so, I presume I will have to replace the existing plastic headlight. Has anyone else done this? Would anyone out there be able to offer me advice on how to proceed? What headlight did you use? What size and brand LED did you use? What size capacitor did you use? What modifications, if any, to the locomotive were necessary to fit in the LED?
A number of things.
1. LED's are polar devices. They light when DC current flows "forward" thru them. They stay dark of the polarity is reversed. If they are reverse biased by more than about 6 volts they mostly die. So if you are running plain DC, you need to do something about polarity. Something can be a full wave bridge rectifier, or a protection diode in series with the LED. Or a bypass diode in parallel with the LED. If you are running DCC, not to worry, the output of the decoders is single polarity.
2. LED's need current limiting resistors. Ordinary LED's must not exceed 20 milliamps. They will be plenty bright with one half that current. Some of the very tiny LED's probably cannot stand 20 milliamps, they will want something less.
3. You ought to be able to find a LED small enough to fit inside existing plastic headlamp on the Consol.
4. LED's are LED's, they all work the same. Your choices buying them are size and color.
5. The so called white LED's are not very white, they show a lot of blue, and don't look much like locomotive headlamps. I'm told that a coat of yellow paint improves the looks.
6. It can be hard to tell which LED lead is plus and which is minus. There are made with one lead longer than the other, or with a flat spot on the housing. I can never remember whether the marked lead is plus or minus. I check them with my multimeter. Ohm them out in both directions. One direction will read a high resistance, the other direction will read low. The lead with the plus terminal of the ohmmeter in the read low direction is plus. Usually the red lead on the ohmmeter is plus, but you want to check that too.
David Starr www.newsnorthwoods.blogspot.com
I have a Bachmann consolidation and have the same idea. I think the headlight is in the smoke box with a plastic rod going into the headlight housing to the lens which is why it is so dim. i am thinking of using a 3mm led and place it directly into the headlight. There are led's smaller than 3mm but I haven't been able to find what I want. 3mm led's can be filed smaller. the tip can be flattened and the shoulder filed down to the same diameter as the rest of the led. I;ve done this when making headlights for some N scale MU cars, so i'm hoping I can get it filed small enough to fit into the headlight. I'm going to use a bright white led and probably a 1500 ohm 1/4 watt resistor in series, not a capacitor. I'm going to put a backup light on the tender as well..
I checked on several other forums and found that some of the Spectrum 2-8-0s apparently already has an LED. After digging up the schematics for my DCC 2-8-0, I see that it lists the headlight as a LEDXX-10084. So it already has a LED and I presume a resistor. It apparently does work with an extremely small diameter plastic rod.
It would appear that the solution would be a larger LED, perhaps 3mm, and appropriate resister. I would then install a larger diameter plastic rod to carry the light forward. It all depends, I suppose, on how much room is in the front of the boiler weight and how easy it is to remove and replace the plastic rod. I would also have to paint the outside of the plastic rod between the boiler front and the headlight.
The lens on the headlight also looks a little foggy and I wonder if replacing it with something clearer might not help.
I prefer to use the Yelogo White LED. It does not have that bluish tint and the Miniatronics set includes the resister. I was surprised to learn that LEDs can be filled flat, that helps with another project I am considering doing. Thanks for the tip.
Before I install an LED I test it with the resister to make sure I have it on the right wire and it is bright enough.
As for the tender, I too want to put a backup light on it, but I am doing the Milwaukee Road and they use to raise the backup light on a stand about one to two feet high on the back deck of the tender. I cannot figure out how to do this with either an LED or a grain bulb, as the relatively thick wire would be difficult, if not impossible, to hide. So I am thinking of either making a prototypical but non-functioning backup light or use a non-prototypical but functional light on the back end of the tender. A compromise I am considering is to place the headlight on the back of the raised coal bunker that was prototypical for the Milwaukee Road. After all, the Milwaukee Road was known as the Resourceful Railroad, so this compromise would be resourceful if not strictly prototypical. (I already built a test raised coal bunker out of styrene, but it is about an HO foot to high and I have to lower it.)
retsignalmtr how do you plan to add a backup light to your tender?
By the way, I replaced the DCC chip that came with the Bachmann with a Tsunami TSO-100 medium steam and am very happy with the result.
It is time to ask the proverbial question...what year are you modelling? Prior to the 1950s it was not uncommon for railroads to operate steamers in the daytime without headlights. An MVProducts lens is a lot easier than re-wiring a 2-8-0
When I made the headlights for my MU car project ,After I filed the led as small as I could get it, I bent the leads down right at the base of the led then drilled two tiny holes through the roof of the passenger car, inserted the led leads and secured them from the inside with gap filling CA. Soldered the resistor on one lead then the decoder wires to both. Then I painted the led with gloss black with the exception of the tip. Looks good, works good.
I am modelling the early 1950s, just before steam was retired on the Milwaukee road. Yes, a lens would be a lot easier, and I might do that on the backup light, but I would like to have a functionning headlight. I already have a functionning headlight, but it is just dim.
I replaced the headlight on my Bachmann 2-8-0 with a 1.5v microbulb, by removing the plastic light rod that extends from the smokebox into the headlight and slipping a microbulb directly into the headlight. I powered it by substituting a homemade TTR light circuit from the M. Rollins site for the circuit board in the tender (I run DC, so the other functions of the stock board could be eliminated by tying the pickup wires to the motor wires directly.) The result is a pleasing incandescent look that fills the entire headlight housing, not just the "bulb". I plan on repeating the process for the Spectrum 4-8-2 I have.
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Gary M. Collins gmcrailgNOSPAM@gmail.com
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"Common Sense, Ain't!" -- G. M. Collins
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The headlight is a 3mm yellow led, if you replace it with a 3mm white led you will get a brighter headlight. I used a Minitronics YeloGlo when I did mine. Replacing it is not the simplest job, you need to take the boiler off, best done without taking the driver and pickups apart. If I remember right you need to separate the frame sides, separation is easy, putting them back together and getting the belt and gears in the right place is the hard part. Make sure you don't pinch the wires putting it back together. I have one with a bad wire that I've put off fixing until I have lot's of patience.
Mike
Old thread I know but I just wanted to chime in after this thread helped me finally build up the courage to replace the measly front headlight in my Bachmann 2-8-0.
Used a tiny LED from Evan Designs, specifically the Nano sized one in warm white if I recall correctly. It worked out great. I took out the factory LED, as well as the plastic channel that goes into the headlight housing (it simply pulled out from inside the boiler shell), I then rewired the LED into the wires available in the model and luckily the 7-19 volt AC/DC rectifier + resistor that comes with the LEDs fits perfectly in the metal light bulb channel cut out in the split-frame.
I then snaked the tiny LED through the front of the boiler and using tweezers, I got it so it was facing the correct direction and I glued the LED to the back of the headlight housing. I painted the back side of the LED black so it would blend in and block light from shining back and here are the results.
Here is a link to the LEDs I used: https://evandesigns.com/collections/hobby-leds/products/chip-nano-pico-leds?variant=32158376067120
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