Week 1 – Turning On & Off

This week, I made a pressure-enabled flashlight using a CR2032 battery & a blue LED. I disassembled one of my AirTag trackers to extract its battery, and got the LED from the shop. My first step was jamming one onto the other & pressing it with my fingers to realize how the device would work—it’s simpler than I thought! I checked the voltage ratings of each & with a blue LED, no resistors are needed.

Enclosure #1

My first attempt at an enclosure design for the flashlight used two rectangles of cardboard. I traced the battery onto a small bit of cardboard, then used an x-acto knife to cut out that circle, leaving the bottom layer of paper intact except for a small perforation in one spot for an LED lede. I then put the battery in its circular spot, cut out another piece of cardboard the same size, and inserted the LED with a lede on each side of the battery, bending up the positive lede to prevent contact by default. I used blue masking tape to connect the two sheets, enabling you to press the device and make it shine.

Enclosure 2

But as incredible as cardboard is, it feels insubstantial as an object and mine looked ratty. I decided thin wood—wood about 3mm thick, since that’s the depth of the battery—could replicate my design with a more substantiative feel. I drew out how this would work, with three sheets:

I found a scrap sheet from someone’s laser-cutting project, & marked it off into thirds. I chopped it out using the band saw. The band saw kept stopping after 10-ish seconds of operation, regardless of whether it was touching material, and shop staff couldn’t figure out the reason, so I had to make a bunch of small cuts.

Since the battery is 20mm in diameter, or 0.78”, I chose the 7/8” forstner bit. While I was planning to use the drill press, I couldn’t figure out how to set it up safely with the grips we had available, so I used a hand drill instead. It required more effort than I expected, but the hole came out perfectly!

After slicing the sheet into thirds and taping, ta-da:

The tape isn’t an ideal mechanism, but wood glue wouldn’t work for this design, and it’s the same color as the light.