A simple I3 lamp to illuminate the hob gear and build plate. Lamp uses (3) 10mm Super Bright LED's, (1) 470 OHM current limiting resistor and a slide on/off switch. Originally spec'd a 68 ohm but lights started fading after a few weeks. The wiring is based on a 12volt supply. Positive lead goes to middle post on the switch, out of switch to 470 ohm resistor, out of resistor to positive lead of led (1). From there led's connect negative to positive with the final led negative connecting to the ground from the power supply. Sorry, I forgot to convert the stl to metric. Good to go now.