twist, solder, glue, repeat

Placing LEDs in the pegboard. (This took a long, long time.) the cutout in the near end of the pegboard is to accomodate one of the power supplies. The cross-braces are 1x1 wooden strips, and prevent the pegboard from bending under its own weight. Because the photodiodes stick up above the table top (down, here), the table is supported a few inches above another table by some cans (cans of corn, mostly). You can see the hot glue gun and multimeter, but the soldering iron is hidden below the table top. Read more here