Monday, September 19, 2011
Bad Wiring? Save the Terminal Plug Before You Trash It
As every vintage sewing machine hunter knows, a lot of times you buy a machine and the seller insists you take the cabinet it's mounted in, because they just want it out of their garage. The first few times that's fun--hey, free desk!--but soon you have more cabinets than you know what to do with.
If you have a Singer that's been wired for cabinet use, it will have a "single lead" power cable with just one set of wires going into the terminal plug. Here's the one from my latest acquisition:
As you can see, this one's in poor shape and needs to be tossed. The wiring insulation looks like it dates to the Eisenhower administration and you can see bare metal. But before we get rid of it, we're going to "harvest" the Singer terminal plug, so that later we can easily--and inexpensively--make ourselves a new power cable.
This here's the terminal plug. It's got two screws holding it together and is super-easy to get apart.
A Brownells bit #150-4 fits the screw perfectly. (Click here if you need to learn about screwdriver bits.)
As you loosen the screws, be aware that the little nut on the other side may fall out of the bottom.
So do it over a towel or carpet scrap, so that the nut doesn't fall out and bounce onto the floor, causing you to get down on your hands and knees with a flashlight trying to find the darn thing. (Yes, that's what happened to me the first time.)
Once you've got the screws removed, the two halves come apart and you see this:
Looks intimidating but it's not. All it is is two wires going into two little brass connectors. There's a third brass connector in the center, but this will be empty for a cabinet-wiring configuration.
The brass connectors just pop right out.
Then you can just unscrew the knurled brass ring, revealing the wiring wrapped around the threaded part.
That wiring pops right off.
Then, do yourself a favor and screw the knurled brass ring back onto the connector before you lose it. Next, cut the wiring outside of the terminal plug and push the remaining wiring through the plug to remove it.
I'm actually going to save this cut-off scrap of wiring, so that later, when we replace it in a future entry, we can copy the knot they used to hold it in there.
After you've removed the wiring, put all three brass connectors back into the plug body.
Then just screw everything back together for safekeeping.
What Not to Do: As you first begin turning the screws, turn them slowly to be sure they're entering the nut at the proper angle. The first time I did this I was in a hurry to get it back together and accidentally forced the screw in at a slight angle. This stripped the end of the screw and ruined the threads inside of the nut, rendering both parts useless. So even though this is a simple little procedure for a simple little part, take your time with it. What I've found in sewing machine repair is that patience is everything; those times that I've rushed something is always when I damage a part or strip a screw.
To turn this into a new, working power cord, you can order the cables with a molded plug right here from Jenny at Sew-Classic, my favorite sewing machine parts supplier. It's only $3.29, versus the $8.69 you'd pay for the molded plug, cable and terminal plug. (She also stocks those right here, by the way.) Not a huge price difference, but if you order just the cables and wire it into the terminal plug yourself, you get the satisfaction of keeping one more piece out of the garbage and back into service. Plus the original Singer terminal plugs have that neat "S" on them.
Just two more things:
One, what I've been referring to here as the "terminal plug" is called, in Singer's original manuals, the "3 pin terminal, female half," just FYI.
Two, I typically drop my bad wiring off at a local recycling center rather than throwing them in the trash. An electronics recycler will take the time to harvest the metal in the wiring and turn it into something useful. If you have a Best Buy near you, they accept old electronics and wiring for recycling free of charge.