The second lightbox was a good success. But then, one dark winter night, a windstorm blew down an old hemlock tree in the front yard. The tree just missed the house, merely busting off a few siding boards. But it totaled the family car, and it splintered the lightbox.
After the tree service cut up and hauled the downed tree away, I carefully picked lots of broken glass and plywood out of the dirt and examined the remains of the box. Amazingly, the LED strips and the electronics were intact — and still blinking away. So, over the following days, I built a new box and installed the salvaged parts.
Along the way, I made a few minor improvements:
This time, I did not line the interior with mirrors. I can always add them later. But I did add a photocell so the controller can shut off the lights in daytime. (It's hot-glued atop a metal stake, visible near the left edge of the photo above.) The lights can't be seen in daylight, and it saves a few watts of electricity.
I also discovered that parchment paper (sold in grocery stores next to the aluminum foil) makes a pretty good light diffuser. For future projects, it will be a tossup whether to use it or packing foam.