The humanoid robot Gort with his laser vaporizing weapon was pretty cutting edge for 1951. He appeared in The Day the Earth Stood Still. Instructables user rragan built a Gort costume for Halloween a few years ago and used a full face motorcycle helmet as the base for Gort. That’s the most recognizable and iconic part of the character’s costume, so that’s the part you want to match as closely as possible. Rragan recommends getting a helmet bigger than your normal size because you’ll need the room for Gort’s weapon.
He fashioned the death ray with Christmas tree lights (you could also use LEDs from our cosplay/costuming section) and a 9 volt battery connector and leads. He explains:
I hit on the idea of Christmas tree lights. We bought new sets last year that are all LED to save energy. I tried one of them with a train transformer and found I could push it up to about 8 or 9 volts before blowing it out. It did get very bright though. However, it was a bit too large for the task.
Then I remembered the little incandescent bulbs that we used before the LEDs. They need about 2.5 volts to light and seemed to handle 6-7 volts just fine. Pairing those with an old 9 volt battery that was only delivering around 6 volts worked great.
I wanted to diffuse the light from the bulbs to give a more continuous light bar effect. I spotted an old used glow stick which looked about the right length. It was translucent and rigid enough to support the bulbs horizontally. I cut one end off and drained whatever fluid was in it, washed it out well and let it dry.
I found that 4 bulbs would fit end-to-end in the glow stick tube. Use two separate pieces of plastic coated wire as long as the tube plus whatever extra length you think you might need for external wiring hookup. Check later pictures for an idea about this.
Take the plastic base off each bulb leaving just the bare copper wires. You are going to wire the bulbs in parallel so one of the little bulb wires will go to one circuit wire (yellow in the picture) and the other to the opposite circuit wire.
Scrape off the plastic insulation on either side of the two circuit wires and wrap the bulb wires around the bare copper. At this point, I soldered the bulb to each wire to get a good solid connection. Repeat this for the remaining three bulbs. Then you can attach the 9 volt battery and test your circuit. If you find the bulbs blowing out, then you could either wire some in series or add a resistor inline to reduce the voltage to the bulbs. Mine worked fine directly.
Read more at Instructables.