Searchlight signals in O gauge are hard to find, so we determined that we would have to make our own. Alan offered to design and 3D print them.
We next needed to find LED’s that would provide the color accuracy and distinct three colors of red, green, and yellow. My son Jim and Alan started searching for LED’s and ordered the best candidates that they could find. Jim found some good ones, but they required us to solder the wires to them. They were so small that it was a very difficult task. Meanwhile Alan ordered some from a Chinese supplier online called Wehonest which were already wired. Jim and Alan tested them for color accuracy and they looked very good.
The next issue was how best to mount them inside the heads. Alan’s first design looked great, but proved to be difficult to install the LED’s in. Alan’s next innovation was great. He designed and 3D printed a Fresnel lens to glue the LED’s to. He then redesigned the heads in two pieces and the Fresnel lens fit snuggly inside the head. I didn’t know what a Fresnel lens was before this, but this is what real railroads use on their signals too. It focuses, directs, and intensifies the light. They are also used in our traffic lights for the same reasons.
Alan recommended a special glue to install them and we had our searchlight head problem solved. I ordered enough LED’s to make all our signal heads, Alan printed all the heads and Fresnel lens, and Jim started assembling them in a production mode.
Here are a few pictures.
LED's with four wires attached to provide the three colors. Red, green, yellow, and black for common.
Alan's final two piece head design. The head is designed to slide on a brass pole. The back is glued on after the LED's are installed in the head.
Alan's design for the backs of the Fresnel lens. The LED's fit perfectly into the cavity on the back.
The front of the Fresnel lens.
Jim holding a LED to show it's size. They are very small to work with.
A disassembled Atlas signal for comparison.
Now we have about 75 heads to build, paint, and find the best way to install them to the signal bridges.
Art
