@TedW posted:Not sure how helpful this will be, but the measurements I could get readily were so different cause the designs were so different. MTH heavyweight was 5mm thick, I installed a 3mm led there years ago. The Lionel streamlined cars have a 3mm “gow” lighting an endcap design, indirectly. Many weren’t lighted at all. So I’m pretty sure one has to approach the task on a case by case basis. But here are some photos if they help any.
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.Thanks for the measurements. I do not have any cars with drumhead lights so this was very instructive as to what the issue is in the first place! I get it now!.
A multi-LED custom PCB may be one way to spread the light...but I'm thinking you would now just have multiple hot-spots..even with some kind of diffuser lens...though perhaps looking better than one glaring hot-spot in the middle.
I've been experimenting a variable filter to "equalize" the distribution of light. I am mindful that there is only about 3mm of depth to work with.
So, for example, I concocted the round filter shown in the inset that blocks more light in the center but then tapers off to the edges. My cheesy drawing program can't draw smoothly decaying gray ring so as shown it's just 4 rings just to mess with. The idea (open to suggestions) is to put a couple layers of diffusing material (plastic yogurt lid), then the filter, then another layer of yogurt lid. So in the end it would be a round 3mm thick filter you plop over the LED to diffuse and equalize the light.
The key is to recognize we have more light than we need to start with.
Again, just a work in progress but I figure something anyone can do at home without special equipment, tools or what not...
