I took inspiration from The Underminer when building my flashlight. I wanted to make a flashlight that is integrated into a hard hat.
My first idea was to take apart an LED bike light, drill some holes into the hard hat, mount it, and wire it up. However, the plan soon failed because I accidentally destroyed the circuit that housed the LED lights with my soldering iron. What I ended up doing was to connect a series of LEDs and make my own circuit. I also built a reflector out of cardboard and aluminum foil to direct the light forward and amplify the light rays.