Illuminated Marker Lamps

I always liked the idea of illuminated marker lamps on cabooses and other pieces of rolling stock but never cared for the way various manufacturers have done this over the years. The markers either look way oversized for the scale or have rather ugly and oversized wires connecting them to the car or both. I have used Ozark Miniatures cast white metal marker lamps on cars for years and they have a nice scale appearance and are molded hollow so that they could be illuminated but using an incandescent lamp would require using external wires to connect them ruining the idea that back in the day these were lit buy kerosene. Through hole type LEDs could also be used but again the wiring issues rears its head. At some point I thought about using surface mount LEDs but how to diffuse the light from one of these as they tend to be very directional. It was then I hit on the idea of turning a piece of clear plastic down to fit inside the lamp casting and gluing the LED to the bottom of the plastic with the emitting side facing up towards the plastic. Seemed like it could work but what about the wiring. Well LEDs are very low current devices so the wire could be really small. I settled on some # 60 gauge magnet wire. This was small enough in diameter that I could thread it through the mounting bracket assuming I could drill a hole through it. So I acquired some surface mount LEDs in a warm white color. These I believe were 1206 size (.012" x .008") and as you can see below are quite small.

I had some 1/4" diameter acrylic rod so I turned down a piece to fit inside the lamp casting and after soldering two lengths of the magnet wire to the LED I super glued it to the clear part. The opposite end was painted with silver paint which I hoped would help diffuse the light even more.

The hole size needed to get the two wires from the bottom of the lamp casting through the mounting bracket was only about half the diameter of the bracket mounting post so it gave me a little leeway in drilling the hole. This was done using a pin vice rather than a power drill as I was concerned about drift at a higher speed. Shown below after drilling.

The jewels that are supplied with the lamps have a reflective film on the back side of them which needs to be removed to let the light through, it comes off pretty easy by scraping with an x-acto knife. The photo below shows the completed assembly. The jewels have been glued in and the lamp to the bracket and the wires routed through the bracket mounting post. A nice clean assembly with no tell tale wiring to give it away.

The most difficult part of the whole process is cleaning the insulating coating off the magnet wire and soldering it to the LED. Patience and a fine tip iron and small diameter solder is helpful. If you have question feel free to email me.