8.10 Campfire √

The only reason I decided to do this was because of the fireflies, since they sprang from the White River & Northern II, which had a campfire as part of the same effects device. Below is a daylight shot of the campfire.

The thing I didn't realize about this old contraption is that it accidentally, more or less, created a spookily realistic effect. I wanted to replicate it by replacing the mechanical device with LEDs, and that proved to be a massive challenge. I began by making an outrageously complex system with 60 LEDs, divided into five banks each with different colors and flicker effects, all bonded to 60 fine optic fibers. It was a colossal failure. My second try had 18 LEDs in three banks illuminating larger-diameter optic fibers. While marginally better, it too was unacceptable.

I was at the point of giving up, when I noticed the fireplace effect I created a for my cabin, which was just two flickering LEDs, was more realistic than either of the fiber optic attempts, so I began to pursue a "pure LED" approach. This too proved challenging because the LEDs would be visible, and it took six tries and dozens of LEDs to come up with a solution, each iteration having fewer LEDs.

The final version comprises just three orange 1.6 mm LEDs arranged in a tight cluster on a tiny scrap of PC board, and wired in series with three flickering LEDs so they also flickered, with brightness carefully controlled by resistors. To enhance the effect, I ground the lenses of the orange LEDs into irregular pointed cones, and covered them with thick gloss gel that I teased into flame shapes with a toothpick as it dried.

Although I don't think the LED solution is as good as the original I'd built back in 1987, it's good enough that it ought to work as long as it's not a foreground feature. Adding firewood and whatnot further improved the effect.

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