List of Materials:
- Wire: 18/2 SJOOW Black 300V Priority Wire --- Link To Source
20 feet will do the motor and the foot controller
- Round Vintage Antique Style BLACK Electrical Plug --- Link to Source
2 each will do the motor and the foot controller
The wire is the closest match to the wire that came on my machine. I've seen some with the braided cloth wire. The source for the plugs above also carries the braided wire.
The wire comes with printing along its length which identifies its construction. This does not match the original look. The printing can be removed easily with Goo Gone.
Use a vinyl or rubber conditioner after to keep the sheathing material from drying out.
Remove the pedal from the base by first pushing the hinge pin out with a roll punch (1/8"). Shoot it with some Aerokroil first to free it up.
Top view of hinge pin in pedal.
Remove cotter pin at opposite end of pedal. If pin is in good shape, it can be reused.
Look at the crud under there. Remove the screw at the heel end of the spring bar.
In order to do a thorough cleaning, remove all of the feet and the securing screws.
There is a plate securing screw under one of the feet.
Interior view of controller, copper contacts, and wiring connections. Loosen the brass wire retaining screw (top left), the wire contact nut (white wire), and the wire contact screw (black wire), then pull the wire out of the controller.
Use 600 grit wet/dry sandpaper to clean the copper contacts. Gently push the contact back enough to slide the sandpaper in and then use the flat side of the screwdriver to apply pressure to the contact as you pull the sandpaper across the contact. Do three passes for each one of the contacts.
Do the same for both faces of the contacts along the other side.
Remove the wire contact screw and plates, then steel wool all surfaces with 0000 steel wool.
To prepare the controller end of the new wire, use the old wire to determine how much insulation to remove.
Cut the black outer insulation with a razor knife, being careful to just score the outer sheathing. You can then pull apart the insulation, in effect, tearing the remaining rubber along the score path. In this way, there is less risk of cutting the insulation of the inner wires.
Separate the inner wires and cut the paper away.
Strip the ends of the wire and tightly twist the strands.
Insert the stripped wire through the grommet in the side of the controller until the outer insulation is flush with the inside of the brass retaining clip and secure the brass screw. Then wrap the stripped leads around the terminal screws, in a clockwise direction, then tighten the nut and the screw. Trim away any extra copper strands.
Now it is time to install the new plug on the other end of the wire. Prepare the wire in the same way as on the other end. Tie an Underwriters knot in the wire conductors and wrap about 8-10 turns of electrical tape under the knot.
This is a close up of the Underwriter's knot.
Strip the wires leaving about 1/2 inch of insulation above the knot and twist the wires.
Slide the base of the plug up the wire to test the fit. What you want is the tape to fit snug into the tubular part of the plug and the knot to sit at the bottom of the dome shaped base. You may need to add or remove some tape to achieve a snug fit.
Wrap the wire clockwise about the screw at each terminal so that the insulation is tight up against the head of the screw and tighten. Slide the two parts of the plug together and install and tighten the outer screws.
Reattach the pedal in the reverse order of taking it apart. Reattach the bottom plate and feet.
I soaked the cast aluminum foot pedal in a bath of hot water and OxyClean, scrubbed with a toothbrush, then buffed with 0000 steel wood, back to the Oxy, then finished with 100% carnauba wax. Turned out very nice.
Tried cleaning with kerosene and a toothbrush for the first time and had very good results with no ill effect to the decals. Lighting doesn't show the decal detail well in this photo. Lightly buffed with Mequair's cleaning wax, then 100% carnauba wax.
After rewiring both the motor and the controller, plug it into the sewing machine to test. This machine runs extremely fast, smooth, and with good control at low speeds.
Hope this helps,
Don't attempt the techniques explained in this article if you don't have electrical experience or are not certified in electronics. Doing so may result in electrical shock and/or death. If you decide to act on these techniques, you are doing so at your own risk. It is recommended to have your work checked by a licensed electrician or certified electronics expert.