My first attempt at the Altoids Puck light. The switch is inside the can and you just twist the two halves to toggle power.

I’m not completely satisfied with this one. It’s a bit sloppy and I need to find a better way to make the holes. The metal bends too easy, maybe a thin coat of a metal epoxy would help before drilling. It uses 3 AAAs for power, and with a 68 ohm resistor drops the voltage to 3.3 at the LEDs.

I’m ordering 100 LEDs (21,000 mcd) from Hong Kong. I don’t have an immediate need for 100 of them, so I might sell half off on eBay to offset the cost.