Step 4: Modifying the Pull Chain

Picture of Modifying the Pull Chain
For the LED to fit in the hole in the metal part of the pull chain handle a bit of material must be drilled out. Doing this prevents the ball chain connector from holding the handle on the pull chain so it is necessary to use a small amount of JB Weld to epoxy the connector to the handle. I affixed the connector to the handle such that the LED's wires can pass through the connector's hole. The epoxy needs to set before continuing. Next I soldered a two lengths of wire wrap wire to the LED's legs so that it could be inserted into the pull chain's handle and reattached to the circuit a greater distance away. I marked one of the wires with a black sharpie to make clear it was attached to the cathode. I used hot glue to insulate the solder joints. After that I threaded the wire through the handle and three pieces of heat shrink, which were on the pull chain. Clear heat shrink would be better, but I only had green. Sewing thread can also be used to attach the wire to the chain, but it caused the chain to kink more than I liked. Attaching the wire to the chain is easiest if the chain is pulled tight. Once I had the pull chain modified, I connected to the lamp and threaded the wires into the diffuser bowl. Doing this allowed me to see how much excess wire I had. Next I took down the pull chain, trimmed the excess wire, discarded the excess, and soldered on two individual, male header pins to the remainder. Then I removed a bit of material from the top of the translucent plastic handle so that it would mate well with the LED. Finally, I inserted the translucent plastic handle.