Latest project .... A reflector with light for my narrow-gauge locomotives. The diameter of the reflector is 4 mm. The LED is 0.5 x 1 mm! The reflector I made out of aluminum from oven trays. I took a nut of the right diameter and slowly pushed the aluminum with the rounded top of the hat from a ballpoint pen. Then I rough cut the edges and filed it to shape with a needle file. I then drilled a 0.8 mm hole in the center of the reflector. I glued the LED to the backside of the reflector with epoxy. The LED is a bit too white, so it'll get a drop of Tamiya transparent orange. Then I'll take Microscale Crystal Clear and fill the reflector so it gets a lens.