Signal Construction Tips
From My Own Experience
Making LED Signals.

If you've been following the experimentation by Bill Payne and me as we tackle building a signalling system for my Utopia Northern layout and the HO layout of the Nottawasaga Model Railroad Club (NMRC), you'll understand that at some point we have to make the trackside signals!

I have some great-looking signals by Tomar Industries that work with the optical boards from LogicRail that I have installed. They operate beautifully and attrack a lot of attention, but it would be too expensive for me to do all my signalling with them. I needed a less expensive solution.

Signal construction is a little tricky. There's an article on the Internet by Peter Pemberton about building your own signals. It appeared in Model Railroader magazine. You can find it on the trains.com website. Peter used signal heads from Oregon Rail Supply. I tracked down some of their kits at a local hobby shop and bought a few extra 3-color signal heads.

Here are a few tips from my experience. I test the LEDs before I start to make sure that I know which end is the cathode (-). These are usually marked by a metal band. I bought some more small 1.5 mm LEDs from Miniatronics and they seem to be marked the same way. It pays to be careful so that you don't get everything assembled and then find out you've wired in one of them backwards. I keep a DC power pack next to me with some alligator test clips and the appropriate dropping resistors: 1000 ohms for the red and yellow LEDs and 470 ohms for the green LED. The 1000 ohm resistor also works for the green. It doesn't matter which lead you use. I usually put the resistor in the negative line. I make it a point to retest after I solder wires to the LEDs before installing them in the heads. You need to tin the wires and the leads. I pass a file back and forth on the leads to make sure any oxidation is removed before I tin them. You want to work fast when soldering so as not to overheat the LED and burn it out. That's why I retest.

I use thin magnet wire and use an X-Acto knife to scrape the enamel coating off the ends. Some modelers burn it off with a lighter. Magnet wire, being very thin, makes it easier to slip the wires through the metal tube. Peter suggests soldering the common anode wire (+) to the mast. I prefer to thread it through the tube along with the other wires. Instead of a brass tube, some modelers have used a straw for the mast, like the smaller ones from fast food restaurants. Obviously, you can't solder to a straw. I have been making single 3-color heads so that only involves 4 wires. If I decide that my signal construction calls for a double head I may try his way. I don't think I could feed 8 wires through the mast tube. I haven't tried that yet. Peter's article says that Circuitron's wire is thin enough to fit six strands inside a 5/64" tube.

I found it helps to deburr both ends of the tube so the wires don't snag. A pair of tweezers can be helpful in prodding the wires through.

After I feed the wires through the mast and before I finish gluing the head assembly to the mast I add a dab of red Testor's enamel to the red lead, yellow enamel to the yellow wire, and I use a black marker to mark the common. As the magnet wire I'm using is green I don't bother identifying it. The reason for doing this is to make it easier to tell which wire is which after the signal is installed trackside. Make the leads long enough that they'll extend through the benchwork. It's usually necessary to add wires to the signals to get from trackside to wherever the logic boards are located. I use telephone wire for this and shrink wrap the soldered joint. It's easier to do this above the benchwork than from underneath. The other option is to make the leads long enough to reach a terminal strip beneath the benchwork.

Here's the set-up I used. Using an X-Acto "third hand" makes it easier to solder the wires, complete the signal construction, and hold the completed signal for painting. I used Polly Scale Aluminum to paint the signals and I left the target face black.

These Oregon Signal Supply 3-color signals
have just been painted

Because I had bought a few extra signal heads I decided to scratchbuild a couple more signals. I had some brass tubing that was approximately the same size. I didn't have a base, platform, or ladder.

Closeup of the Oregon Signal Supply assembled model

We plan to install four signal blocks on the grade from Valleyview. There are two tunnels on the grade and the signals will be placed in front of the tunnel entrances.

Closeup of the scratchbuilt signal

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