I have received several comments from readers on how to rewire their old Vintage Singer sewing machine. The need for this is all too common on the 1950 and earlier vintage machines. While the sewing machine itself is built to last neigh on forever, wires do not. Typically, the wires become brittle and the insulation crumbles and exposes bare wires. I think re-wiring falls into three categories, since the power terminal supplies power to the motor and the light, and the foot controller wires also share the same fate. For this tutorial, I am going to focus on the motor and wiring to the terminal block. Whereas this tutorial can be be generally applied to more than one type and vintage motor, light fixtures fall into several styles. Some are easy to rewire, some are quite difficult. for the purpose of this tutorial, I am only considering the motor.
This is a very complete restoration. I am restoring this for a sewing machine that is undergoing a detailed restoration, so I decided to exerpt the steps here. For this reason, you may not need to follow all of the steps I take. You may simply be interested in replacing the wires… so you may skip steps as suits your needs… or dive deeper. In any case, all of the steps are shown.
I am also going to rely on less words and more pictures captioned to explain the steps. Discussion will be limited to what I consider to be important or relevant to completely describe the steps involved… so here we go.
This is a Singer BR8S 0.5 amp sewing machine motor that is fitted to a model 15. It uses grease wicks for lubrication and is a very well built and durable motor.
The first step is disassembly… To make things easier, remove the wire plug terminal and the motor bracket.
Now, I mentioned that the brushes should slip out freely. If they don’t, it means that grease has made it’s way into the brush tubes. This condition will require motor disassembly, and your wire replacement becomes a bit more complicated. No worries, it merely means a few more steps are needed.
Next the commutator and shafts are polished. To polish the commutator I use jewelers rouge and a dremel tool. As a substitute you can chuck the shaft in a drill and use 2500 or 3000 grit wet/dry sandpaper to polish the commutator. To polish the shafts, I use 2500 grit sandpaper wet with a few drops of sewing machine oil and spin the shaft in a drill while running the sandpaper up and down the shaft. It results in a glass smooth finish. Repeat for the other end of the shaft.
Inspect the brushes for wear. They will have a curved face where they contact the commutator and wore to the circumference of the commutator. Because the commutator shaft is polished, they can either be left curved, or flattened with 600 grit sandpaper. These brushes are in great shape, so I will leave them alone. If your brushes were stuck and covered with grease, clean them with alcohol. Now clean the brush tubes with alcohol and a cotton swab.
WARNING: Do not get alcohol or any solvent near the thin wound wires… they are the thin wires that form the windings on the armature shaft and field coil windings. They are coated with lacquer to allow them to be wound without shorting on each other. Alcohol and solvents dissolve this coating and it will RUIN your motor… no kidding.
Notice the grease wick I showed in the bushing in the picture captioned above. It was free to pop up into the bushing when the shaft was removed. If your wick pops up, thats very good news indeed. If the wick does not pop up, it must be either removed or freed to move. It must contact the shaft to deliver lubrication. Removing the grease wicks and spring that applies the pressure needed to keep the wick against the shaft is a very tricky maneuver. I would recommend trying to remove it only if necessary and you are prepared to replace the wick… be warned, these are 1/8″ F12-14 felt wicks and are not easy to obtain. Free them instead. To do this, try gently pushing a sewing machine needle or toothpick into the grease port to push the wick down into the bore of the bushing. Now push the wick up by using the side of a needle or toothpick against the wick in the bore. Repeat these steps several times and look for the wick to free itself up sufficiently to pop down into the bore on spring pressure alone. The following picture shows the wicks removed and these springs.
The motor housing is cleaned and the wicks are reinstalled in the motor housing.
Next we will go to the wires. Generally, the only wires that need replacement are the field coil wires… the ones that exit the motor. The brush tube wires are cloth covered and likely in good condition. The brush tube wires on this motor are in good condition. If not, it is a simple matter of de-soldering the wire from the brush holders and replacing the wire.
The wire I am using for the replacement is 18/2 stranded lamp wire. It is available at Home Depot in a 10 ft length package for under 2 bucks. It is the proper gauge without the insulation being too thick. Remember, the motor has limited clearance for the wire in the case, and does not need to be occupied by excess wire insulation. This wire is also a good choice for rewiring the light. For controller wiring, I think a 6 foot extension cord works great. The insulation is thicker and better for overall durability in use. First, the wire will need to be split. Start a cut in the groove between the 2 wires and simply pull it apart… pretend it is taffy and it will peel apart without too much effort.
Reassemble the motor in the reverse order. Don’t forget the washers on the shaft ends. Also, the motor center casing has an orientation. Observe the shape at each end and you will see if it is correct. READ THIS: Now the next step is very important and I will describe it in detail.
The grease wicks should be protruding in the shaft bores. If you push the shaft in without pushing the wick up first, you will cut the wick in half and render it useless. This step takes some dexterity but is simply done… Gently start the shaft into the bushing until it rests against the wick. Use a toothpick to push the wick up into the wick tube. When the wick is flush with the bushing bore, slide the shaft over the wick and seat it in the bore. On the end with the wires, pass the wires thru the grommet hole in the motor casing before inserting the shaft. As you slide the shaft into the bore, you will need to pull the wire to remove the slack. Once the shaft has cleared the wick and the wires are pulled thru the grommet hole, you are home free.
After assembling the motor, make sure it turns without the armature or fan hitting a wire. You will probably notice this before the motor casing closes together completely, but If it does hit, the wires can be cleared with a small screwdriver inserted in one of the vent holes to push the wire out of the way.
Replace the cap on the end of the motor.
Reinstall the brushes so the curvature matches the orientation of the commutator. GENTLY screw the brush caps over the brush spring. Be careful that the spring does not escape and fly across the room. If it does, chances are you will never see it again. The brush caps do not need to be tight… nor should they be. Tighten it about “thumb nail” tight and smile with satisfaction that the motor restoration is done!
Now that the motor is reassembled, the connectors from the old wires are soldered to the ends of the new wire. This is why we saved them when we cut the wire during disassembly.
Before the motor is installed, it must be lubricated by filling the grease tube reservoir. The motor lubricant I am using is plain old 100 percent petroleum jelly (not Vaseline) it must be plain petroleum jelly with no other additives. This is generally the economy brand… just look for “100%”. By the way, I am not going to get into a discussion here about it’s suitability as a motor lubricant… the world wide web has much discussion on this topic. Suffice it to say, there is not much demand for grease wick lubricant for these small motors these days and as a substitute, petroleum jelly possesses the necessary melting point to lubricate these motors. Both Singer and White sewing machine literature on the subject recommends it. Inject the lubricant into the grease tubes with a small syringe packed with the lubricant (oral syringes available at any pharmacy work great)
That said and done, reinstall the bracket on the motor and bolt it to the machine… don’t worry about the belt. you will put it on after this is complete and the motor is run in.
Wiring to the terminal block is easy. The back of the plug is numbered 1 thru 3. The new motor wire goes to terminal 2 and 3. The light wire goes to terminal 1 and 3. If you are going to hard wire the controller, the controller wire goes to terminal 1 and 2. I prefer not to hard wire the controller and use a power cord that has 2 wires leading from the plug. In my opinion, it is more convenient to allow the controller and plug to be removed from the machine.
Before installing the belt, you will need to run the motor to “seat” everything in evenly. Power the machine and run the motor at full speed. You may notice its speed increasing as you run it. I recommend running it until the motor feels warm. Feel free to vary the speed thru this process.
Install and tension the belt and you are ready to go!
I hope you found this tutorial useful, and if you do decide to follow these steps I think you will be pleased with the renewed strength and speed your restored vintage motor will deliver… Also, I don’t think there is a sewing machine motor manufactured today that is close to the quality of these old vintage motors.
I Hope this helps! and please visit our Etsy store at https://www.etsy.com/shop/pungoliving to see our selection of restored fine quality vintage sewing machines.
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