Build a flashlight using any tools or techniques. Flashlight is defined as portable and creates light.
I needed a hands free source of light for rummaging around my garage, aka the cabinet below the sink my city apartment. It’s crammed with candles, cleaning goods, tools, extra supplies, recycling, and whatnot, and I usually blindly feel my way through the mess instead of hauling it out onto the kitchen floor. It’s terribly inefficient. I could install a proper light, but a wristband flashlight might do the job and serve me well in the future when I venture into the deepest corners of my crowded closets.
With this idea in mind, I immediately found several related projects on Instructables (Handy Dandy Flashlight and Flashlight Wristwrap) and at Adafruit (LED Friendship Bracelet) and gave myself several parameters:
The light needed to be directional as in the Handy Dandy Flashlight to help me find that doohickey under my sink.
The circuit needed to be simple. My current understanding of electricity is rudimentary at best and truly just beginning (over here). I know the electrons in the negative terminal of a battery strive to reach to the positive terminal, and on their way there (via the path of the circuit) they can make things happen, like a light a LED. This Instructables Robot Paper LED Flashlight showed me that I could sandwich a coin cell battery between the leads of a LED, with the positive terminal connected to the positive lead (anode) and the negative terminal in contact with the negative lead (cathode). Adafruit’s LED Friendship Bracelet gave me the idea to slip the battery into a pocket to keep those leads in contact without using my other hand to apply pressure or creating a separate switch of some sort--just insert the battery to complete the circuit.
Finally, the wristband needed to be comfortable and accommodating to multiple wrist sizes, not just my own. I want to share!
Materials & Tools
1 Sweat Wristband (from this summer’s Afropunk Fest BK!)
1 White LED
1 3V Coin Cell Battery (CR2032)
⅜” Inch Wide Conductive Fabric Tape
While I’m pleased that the final work matched my vision, it quickly became clear that you really have no idea how the materials will behave until you start turning, bending, and working them by hand. Though I was very fortunate to find working conductive fabric tape, the adhesive was not exceptionally tacky. It bunched and twisted easily, and if not careful, the much-stronger velcro tended to snag and pull it off completely. For the next iteration I might use wider conductive fabric tape and also sew a more secure attachment along the edges of the tape. It’s tough to do by hand, so I need to learn to use a sewing machine to see if that does the trick. I'd clean up those rough edges around the velcro, as well, to prevent fraying.