3. BUILD YOUR BOXEN
L1. 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.
L2. 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 250m W red diode laser from Sunclan ( 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.
L3. 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
L4. Finally, attach the lumia disk to the motor, pop it all into your
box, and shine on, you crazy diamond!