Ski Rack
First Generation
Many moons ago I created an accident scene in the middle of an intersection for my White River & Northern IV. It served two purposes: one, it was kind of fun to see, and two, it justified having streets full of perpetually parked cars.
With a lack of SMD LEDs back in the 1990s, I used microbulbs driven by an old flashing trade show button chip. It was big and bulky, but it's what we had back then. One of the two police cars from the scene above survives as it was originally built on Rick Spano's layout:
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Second Generation
I'd always wanted to do it over with modern LEDs, so I created one for the Newport & Rock Falls II, a retro layout project.
To make the ski rack, I drilled a series of holes in a strip of styrene, and installed five 0402 LEDs, two each read and blue, and one white in the center.
Then I installed the ski rack (above) in the car, and made a cover for it from thin frosted acetate (below).
The ski rack is controlled by an old button flasher, the same kind I used the last time I did this back in the 90s.
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Third Generation
This one is similar to the second gen light bar, except built to tighter tolerances. In this case I made an all-amber light bar for a tow truck on the Men At Work diorama. It's a bit bulkier than I'd prefer, but some of the bulk is hidden behind the tow truck's roll bar. First, I drilled two rows of five #80 holes in a strip of thin black styrene, threaded the LED wires through them, and bonded them in place. Then I drilled a row of recesses in a piece of old styrene clear glazing material, trimmed it to size, and sanded it to shape. Finally, I bonded the clear part over top of the LEDs, and installed it on the truck. You can see it working in this video:
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Of note, I utilized a different means of making the LEDs flash: instead of using an old flashing circuit, as I had with the first and second gen units, I wired each light in the rack in series with a quick-flashing LED. I think it works better than the flashing circuit.
Fourth Generation
After a couple of spectacular failures, I returned to a variation of the third gen, with a side of neon OPEN sign thrown in. The problem was this: the tow truck rack worked fine with five lights, since they were all the same color. But for a convincing red/blue light bar, I needed to up the ante to six (3 red/3 blue) or seven (3 red/3 blue plus one white) LEDs. So I went full-tilt boogie and built a seven-LED bar. It was terrible. The lights all blended together, and there was no sense of flashing, just kind of vague pulsating, with the white LED nearly washing out the red and blue. So I backed it down to six lights, which gave me just enough room to segregate the LEDs with barriers so the flashing could be more pronounced, this being the OPEN sign influence.
After installing the six LEDs in twelve holes drilled in thin black sheet styrene, I added dividers between the LEDs and then started trimming (above left). At this point you may think it looks pretty gross, but it's how it works that counts. My next step was a bit counterintuitive, but then some good ideas often are: I lightly sanded the dividers to make an oval-top shape, then applied a piece of plain old scotch tape. This created an enclosure without adding any bulk. A little CA along the edges kept it all together (above right).
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The rest of the project was just an exercise in loading up my model police car with more LEDs: headlights, parking lights, and tail lights added eight to the six of the ski rack for a total of 14 LEDs in once vehicle!
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Later, after referencing some videos, I decided to add a bit more action to the car. I tied the headlights (white), parking lights (amber) and tail lights (red) into a flasher circuit, as shown below. However, I also added a switch so I could optionally flip between flashing and steady, just in case it got to be too much, although the light bar ran either way.
