Lumia Lunchbox Laser

Assemble the voltage regulators.

Count the number of voltage regulator circuits you need to build your boxen. Each Lumia box needs 2, a Diffracterator needs 4, and a Motiondizer uses 1.

Cut a section of perf board for each box and follow the circuit schematic in the documents section to assemble its voltage regulator circuits.

If you’re using a laser stronger than 10mW (or want the option to swap one in later), put a heat sink on the LM317 voltage regulator.

Note that all the individual regulator circuits share their connections to power, diode D1, and capacitors C1 and C5.

Make the internal frames.

For each box, start with a base plate made of 3/8″ plywood. Measure the inside of your box at the bottom and cut a piece of plywood to fit, giving it 1/8″ or so of space all around to make removal easier. All the gizmo-ry gets built onto the plate.

Attach side rails to the plate, sized to reach the top corners of the lunchbox. The rails keep everything from falling when the box is on its side, and they also provide places to hang components and serve as convenient handles for removing the workings from the box. I made mine from some erector-set-looking metal stock screwed into ½” blocks of wood glued to the base plate, with the corners secured with pop rivets.

Paint the base plate and rails flat black to prevent random internal reflections.

Now you’re ready to make some laser lunchboxen! Instructions for Lumia, Diffracterator, and Motiondizer follow. The Lumia is a good place to start because it’s the simplest; all you need is 1 laser, 1 motor, 1 lumia wheel, and 2 voltage regulators. For all boxen, the simplest versions use a smaller laser, say in the 5mW neighborhood, which won’t require a heat sink and fan.

Build your boxen: the Lumia.

Make the disk, from plastic or glass. For plastic, glue a washer that fits the motor shaft to the center of a CD spacer. For glass, cut the disk (or have one cut) with a glass cutter and glass drill bit.

In a well-ventilated area, apply model glue or clear epoxy to one surface of the disk, smearing it around with a toothpick to make an irregular surface. These disks can be an endless source of experimentation and amusement as you try different combinations of glue, plastic, glass, and whatnot.

Figure out your component layout on the base plate. If you’re working with a higher-powered laser, leave space for heat sinks and/or fans.

For the motors and laser, position them to minimize footprint and maximize adjustability, so you can fine-tune the beam paths until you get everything dialed in. I usually screw in just one end of the mounting straps, and only screw in the other end after everything is lined up.

With our Lumia device, we used a big 250mW red diode laser from Sunclan (http://clantechlaser.com), so the laser and LM317T regulator are both heat-sunk, with a fan blowing on both. The laser is aimed at a front surface mirror, following the usual configuration, but if your laser is small enough you may be able to skip the mirror and just aim it straight up through the wheel.

Attach everything to the base plate, and adjust. To attach the circuit boards, we used 2 methods. I mounted mine directly to the base plate using wood screws; the plywood acts as an insulator. Wayne mounted his vertically using small angle brackets, which minimizes footprint and provides access to the bottom if you need to tweak the wiring. With pipe straps, you can use the existing perforations for screws, and drill extra holes if the spacing is off.

Assemble the device outside the lunchbox, but periodically put it in to make sure everything fits. As you go along, make sure the laser is happy; warm to the touch is OK, but if it’s burn-your-finger hot, add a fan. Also check that the motor turns at a nice slow speed; <1rpm is best, but adjust to taste.

Finally, attach the lumia disk to the motor, pop it all into your box, and shine on, you crazy diamond!