November 1999. These images are of a LEGO compatable slip-ring unit designed to fit within a Technic turntable. The main component is a telephone cord untangler purchased from Radio Shack. I straightened out the wires on the RJ11 plug and removed the plug housing leaving only the wires and the inner plastic tube. Then this end was glued into a stack of two Technic plates, one 2x6 and then a 2x4. The wires were then soldered to the bottom side of a 2x4 electrical plate modified into four contacts by cutting the metal traces with a Dremel tool. The receptical end of the cord untangler was cut off and insulated wires were soldered onto the original internal contact wires to extend them. This end was potted in epoxy to stabilize and insulate the internal contact wires as well as the four extension wires which now exit from the side of the housing. These wires were then soldered to another modified 2x4 electrical plate. It would have been much easier to just connect to the extension wires inside of the receptical end without cutting it off, or even use an RJ11 plug, but I was trying to minimize the final size of the device. As it is, the finnished slip-ring unit fits within a LEGO turntable unit and is currently sitting in the directional head of my synchro-drive robot.
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