A Singer 401a and Greasy Terminal Prongs

Hi everyone, I know, long time no talk. I recently got to meet Elizabeth from My Sewing Machine Obsession and that was pretty cool. She mentioned that I hadn't written in a while. Over a year!

I've been busy with work and fixing sewing machines on the side, even making housecalls in Manhattan. If you need repair work done on your machine, are in NYC and/or can bring your machine to me in lower Manhattan, drop a line.

Anyways, a customer brought this Singer 401a to me. She came my way from Peter Lappin's sewing blog. The customer had just purchased the machine from a "reputable" seller online, and the machine had been damaged in shipping, with one spool pin broken off. She asked if I could fix it, I said no problem.

When she arrived with the machine, she mentioned that after five minutes of sewing, the machine would begin to emit a smell. I told her I'd check it out.

Well, never mind the spool pin, I was appalled to see the condition of the machine. So much so that I subsequently looked up the seller. I will not mention him by name, but based on his reputation and self-description, any of us would probably buy a machine from this guy in a heartbeat. He has been working on machines for longer than I've been alive, so I cannot understand how he let these things go.

The first thing I went to do is plug her machine in to uncover the source of the smell, but I stopped dead in my tracks. Check it out:

See that green stuff? Old Singer lubricant (grease) turns that shade of green after many years, I've seen it inside plenty a machine. And here it is on the terminal prongs--not good. Even worse, there was more on the cable:

Folks if you ever see this, do NOT plug your machine in. Electricity should never mix with oil, grease, or any kind of lubricant. The woman who brought me the machine is lucky that the machine didn't start a fire.

It's not difficult to clean old grease off of metal, you just go at it with Q-tips and rubbing alcohol. So I'm really surprised the seller was so careless. Here's the terminal after I cleaned it:

However, I was not able to get the grease out of the power cable. There's no way I can see inside, so there's no way I can ensure I've removed every last bit of grease. I told the customer her cheapest option was to order a replacement cable from Sew-Classic. Since it's only $6.99, it really bothered me that the original seller didn't supply one rather than the grease-soaked one.

The rest of the machine wasn't much better. There was an antique-looking piece of thread jammed under the hook assembly, providing friction:

It took me a little time, since it was wound around the shaft, but I fished the thing out. I estimated it was 8 inches long, but I measured it just now out of curiosity and it was a foot.

And the rest of the machine was just filthy. I don't mean the body of the machine, which almost doesn't matter--that's basically cosmetic--but the working parts of the machine, like the tension assembly. I stripped every part that needed it to give it a thorough cleaning. Here are the before-and-after shots:

I saved the spool pin for last. I'm sorry I don't have photos of this part, but I'll explain how to do it in case one of you needs to. With a 401, you have to take the lid holding the spool pins off. I futzed around with the hinges for a while trying to figure out how to remove it without breaking it, then finally realized you just keep moving the lid in the open direction, gently, until it pops off. (This is only the second slant-needle machine I've worked on, I'm usually doing older cast-iron models.)

Then I was going to hammer out the spool pin using a hammer and a blunt nail, which is how I've gotten broken spool pins out of the base of a 201-2 and 15-91 (where you place the spool for bobbin winding). But after clamping the lid upside down to my workbench, I worried that hammering it out might bend the lid.

So instead I drilled the spool pin out, since it was plastic. What you do is start with a 1/16th" bit and drill through the center of the broken spool pin. (Try to get it as dead-center as you can, because you don't want to hit the metal part of the lid and potentially ruin the hole.) Then you just drill through the hole with progressively larger drill bits, and eventually the spool pin fragments just disintegrate and fall out of the hole.

That's the tricky part. Replacing a plastic spoon pin is easy, you just wedge it in there manually, you don't have to tap it in with a hammer like you do with a metal spool pin.

Using one of my own grease-free cords, I spent twenty minutes stitching the machine in and running it full-tilt. No burning smell, and a nice, strong-running motor in this machine.

There's a couple of things I want to say. While I cleaned the customer's machine for a few hours, I didn't give it what I call the "Million-Dollar Treatment," where I slave over a machine for weeks or even months as a time-consuming hobby. Because I think no customer is going to pay for what I'd have to charge them for that kind of time. So I didn't get into every last nook and cranny but instead cleaned up the most offensive and function-affecting areas.

Secondly, to be fair, I do not know what condition the original seller received the machine in. Maybe it was a total train wreck and he brought it back from the dead, and maybe I oughtn't malign him?

Then again, there's no excuse for neglecting basic safety. Yeah, that settles it. Far as I'm concerned the grease on the power cable is a damning indictment. Can you imagine if this poor woman had burned her house down over a sewing machine? Folks, if you're ever going to buy a used machine, please do inspect the terminal and power cable carefully to be sure they're not covered in grease.

I don't mean to be sensationalist or self-promoting. I have never, ever heard of someone burning their house down in a fire caused by a sewing machine. But common sense dictates that any sewing machine repairperson ought to do their best to minimize those risks. It took me less than fifteen minutes to get the grease off of the prongs, and ordering a new cable takes less time than that. Those things should have been done during the initial refurbishment.

If you see that green grease on your terminal prongs, clean it off with a Q-tip and rubbing alcohol, then give it plenty of time to dry off before you plug it back in. And if your power cable has grease in the ports, recycle it and buy a new one--$6.99 is a small price to pay for peace of mind.

How to Remove & Re-Install a Tabbed Stop Motion Clamp Washer

In the previous post, we looked at how to remove and re-install the stop motion clamp washer on a potted motor machine. But many other vintage Singers (like the 66, 99, 206, 306 et cetera) will have a different washer, as seen in the photo above. Here's how you tackle that one:

How to Stop the Needlebar from Moving During Bobbin-Winding Mode

When you set your vintage Singer sewing machine into bobbin winding mode, by cranking the stop-motion wheel counterclockwise, the needlebar is supposed to stop running. This is to save unnecessary wear-and-tear on the machine, and prevent you from having to unthread the needle to wind a bobbin.

However, if a few crucial parts of your machine are dirty, the needlebar will continue to move even though you are in bobbin-winding mode. This is easy to fix, and I've made two relevant videos, below, to assist you.



This first video explains the parts of your machine involved in engaging and disengaging bobbin-winding mode. If you are not interested in the mechanics of how your machine works, you can skip this first video (though some of you may find the "X-ray" part that starts at 3:15 in the video to be informative).



This second video, below, is where I show you how to actually fix the problem. The video may seem long, since I'm over-explaining things; but once you understand how to fix this, you will be able to fix this problem in mere minutes.



Note: If your stop motion clamp washer doesn't look like the one in the video, but looks like this one below...

...then click here to see how it goes on.

The oil I'm using in the video is Tri-Flow oil, my favorite. If you cannot find it near you (it's often sold at bicycle shops), here's an Amazon link:



Happy fixing!

Reader Questions: Eric's Knee-Operated 15-91

All photos in this entry by Eric from Ottawa

Eric from Ottawa writes,

[The 15-91 I recently acquired] looks like it's in great shape, but it doesn't run. It has a knee switch rather than a foot pedal and it looks like the motor controller has failed. 

To test it, I unscrewed the center of the flywheel so there was no load and plugged it in and got nowhere, even with the knee switch in and fully engaged.

Do you think it's worth re-wiring it to use a standard foot pedal like most of the ones I've seen?

Hi Eric, first off, a little about your machine. The chrome rim on the handwheel plus the design on the faceplate, from the little bit of it that we can see in the photo up top, indicate this machine is from the 1930s or early 1940s (assuming those parts are original). The old-school cylindrical Singerlight visible in the photo below also indicates the machine is from that era.

The “J-“ prefix on the serial number plate indicates your machine was made in Singer’s Canadian plant in Quebec.

Secondly, good on you for trying to run the motor with no load, that’s exactly the correct first step to test out a motor.


As you’ve observed, your machine uses a knee-activated controller.
 

For those readers unfamiliar with this device, it was an early alternative to the foot pedal most of us know, and it eventually fell out of favor. It consisted of a motor controller placed in the right side of the wooden base:

The end of the removeable knee lever--which stows handily inside the case and underneath the machine, or occasionally up in the domed lid via clasps, when not in use--“plugs” into the hole in the front of the case.

Pressing against the lever would activate the motor controller, which is wired into the inside of the three-pin terminal.

Eric, there are three possibilities here: 1) The power cable is faulty. 2) The motor controller is faulty. 3) The potted motor itself is faulty. Hopefully it is #1 or #2 and not #3, as the first two are easy, relatively inexpensive fixes.

To see if it’s the power cable, try turning the light on. That’s not a 100% accurate test because the bulb may be burnt out, but at the very least, if the light does turn on you know there’s power flowing through the cable. Another thing you can do is bring your cable to the house of a friend with a vintage Singer--that cable will fit a variety of machines made in the 1930s, ‘40s, ‘50s and some in the ‘60s--and see if it powers his/her machine okay. If you determine your cable is what’s faulty, you can order a replacement from Sew-Classic for US $7.95 right here. If you choose to go with a different supplier, perhaps someone local to you in Canada, note that you’re looking for a “single-lead” (as opposed to “double-lead”) cable.

If the motor controller is the problem, it is totally “worth re-wiring it to use a standard foot pedal,” to answer that question, and the good news is that it doesn’t quite require “re-wiring.” The motor controller leads are easily removed via two thumbscrews inside the three-pin terminal. There’s no cutting of wire or soldering required, it’s a simple mechanical connection. To see how to remove the leads, click here and look at the parts of the entry that pertain to removing the two motor leads, which in your case are really the controller leads. Be sure to note which two pins in the terminal those leads connect to.

To replace your motor controller with a foot pedal, you’ll need to spend a tad more. You’ll need to buy a foot controller; the least expensive offered by my preferred supplier, Sew-Classic again, goes for US $11.95.

What you can do is connect the two leads from your new foot pedal to the same two posts that you disconnected the original motor controller leads from. Then you can remove the old motor controller (attached via screws) from that compartment on the right of the wooden base, and store the pedal there.

Alternatively, if you’d like an original Singer foot pedal, you can check eBay.

If it’s the motor that’s bad, then you’ve got a fair amount of work ahead of you to figure out what exactly is wrong with it, and if it’s fixable. You may want to browse the complete “How to Re-Wire a Potted Motor” to determine how to disassemble the motor so that you can inspect the wiring, one possible culprit. But if it’s something beyond bad wiring--a burnt-out field core, for example--that’s beyond the range of my fix-it knowledge.

If you do determine the potted motor is what’s faulty, you will occasionally spot someone selling one on eBay.

Whatever you do, please don’t throw that motor controller out, even if you determine it’s bad; if you stay in this hobby long enough, you will eventually encounter someone else who may need a part from that controller--even if it’s just a single screw--so you may be able to help them rescue an otherwise non-functioning machine. Ditto with the knee lever.

Best of luck with it, congrats on the machine--I love those chrome-rimmed handwheels!--and let us all know how it turns out.

The Complete “How to Re-wire a Potted Motor”

If you are arriving at this entry for the first time, this is a comprehensive guide on how to re-wire the potted motors found on vintage Singer 15-91 and 201-2 sewing machines. It is my attempt to walk someone with zero experience through the entire process.

For your convenience, here are links to all 20 entries in the series. This way you can bookmark this page as a Table of Contents and quickly get to the entry you need.

Part A: Skills Building

1: Wire, Wire Stripping and Wire Braiding
Learn about the tools and wiring basics you’ll need to know to re-wire a motor.







2: Tools & Materials Required for Soldering
Learn what equipment you'll need to complete basic wire soldering.

3: Learning to Solder
Learn and practice basic wire soldering.

4: How to Terminate Your Wires
Learn how to create connections for attaching wiring to power terminals.

5: Covering Wire Joints with Heat Shrink Tubing
Learn how to clean up exposed wiring.

6: The Underwriter's Knot
Learn how to tie wiring into a strain-relieving knot.










Part B: Motor Disassembly

7: Disconnecting the Motor Leads
Learn to detach your sewing machine’s power terminal and wiring.

8: Motor Housing Removal
Learn to take the motor off of your machine.

9: Grease Wick Removal
Learn how to remove those grease wicks and where to get replacements.

10: Motor Brush Removal
Learn how to take those motor brushes out and look for signs of motor trouble.

11: Armature & Worm Removal
Learn to remove two crucial parts of your motor.

12: Detaching the Field Core
Learn how to safely crack the motor open.







 Part C: Making Repairs

13: Cutting and Prepping the Motor Leads
Learn where to cut the bad wiring off.

14: Replacing the Motor Housing Grommet
Learn how to remove a cracked rubber grommet, where to get a new one, and how to put it in.

15: Soldering On New Motor Leads
Learn where and how to solder on the new wiring.

17 (Yes, this is out of sequence): Cleaning the Commutator
Learn how to clean off a crucial element of your motor.







Part D: Motor Re-assembly

16: Re-attaching the Field Core
Here we start putting the motor back together.

18 (Yes, this is out of sequence): Re-installing the Armature and Worm
Learn the tricks behind putting these two crucial parts of your motor back together.

 

19: Re-installing the Brushes and Grease Wicks
Learn to easily re-install these correctly.

20: Hooking It All Back Up
Here in the final step we finish up the wiring, run the motor in, and put it all back together.








[A caveat: I hope you'll be able to bring your potted motor back to life with new, safe wiring, as shown here. But please be aware that these steps are not an absolute guarantee of success, as a small percentage of motors may be completely burned out, which is currently beyond my capabilities.]

How to Re-wire a Potted Motor, Part 20: Hooking It All Back Up

Now we’re at the final step to getting your machine back up and running!

Start by sliding your newly-renovated motor onto the shaft.

Tighten the two motor mounting screws securely.

Then, unscrew the terminal body. Note that I’ve tucked the two motor leads behind the terminal mounting bracket. This is so that we can determine the proper length to cut the tails.

Now we’re going to make new connections on the ends of the wires. As we went over in Part 4, you can either make your own eyelet and solder it, or use crimp-on connectors.

Option 1: Self-Made Eyelets

The self-made-eyelet-and-soldering route requires plenty of wire, which is why we’ve left the “tails” of the motor leads so long. You’ll need to calculate where to cut the wire such that you’ll have plenty of material to form your ring. I suggest measuring and practicing on a scrap piece of wire first, so you can be certain where to cut and strip in order to produce a ring that will still reach the post it needs to connect to in the terminal body. If in doubt, cut too long, not too short!

Option 2: Crimp-On Connectors

Here I’m going to do crimp-on connectors, which requires less length and is easier for me to execute. I generally determine where to cut by letting the terminal body hang naturally, supported by the lighting wires that are still connected, and then drawing the motor lead over the knob that it will fit under. I then pinch the wire to the side of the knob furthest from the motor, as shown in the photo, and cut there. This will make the final wire long enough that I can comfortably manipulate it into place.

Next I strip the wire ends to the length required for a crimp-on connector, just 1/4" or so.
 

Then I gather the connectors and, very important, I immediately cut two pieces of 1/8” heat shrink tubing about 1/2" long.

I slide the heat shrink tubing onto the wires first…

…and only then do I attach the connectors and crimp them on.

Then I slide the heat shrink tubing down into place, as seen below. You’ll notice that now I’ve pulled the motor leads OVER the terminal mounting bracket.

I’ve done that so that I can get the wiring a good distance away from everything else, to comfortably fit a lighter under the heat shrink tubing.

Now they’re heat-shrunk and ready to go.

Re-Attaching the Wiring
When the ring connectors are ready, tuck the wiring back UNDER the mounting bracket, in their final position. Pull the red and black wires over to their appropriate posts on the terminal. (Here I’m working on a 201-2, which has a light switch, and you’ll observe I’ve had to thread the black wire underneath a different wire that arches over it, connecting the light switch to the red post.) If you have a cabinet-mounted machine, connect the foot controller wires too, even if the machine isn’t in the cabinet yet. We need to do some testing.

After connecting the right wires to the right posts, we tighten up the thumb screws. Get all three of them as absolutely tight as you can with your fingers.

Now it looks like this. Be sure you’ve got the motor leads tucked BEHIND the bracket…

…then screw the terminal back into the machine. Do NOT overtighten this screw. The terminal body is made of plastic and easy to break. You only want to get it tight enough that it doesn’t wiggle around when you plug the cord into it.

I’ve grossly overexposed the next shot so you can see how the motor leads come down unobtrusively from the motor and disappear behind the mounting bracket.

Now we’re at the moment of truth!

Running the Motor

I plug the machine back in without re-attaching the handwheel, because I want to run the motor with no load--that is to say, not powering the rest of the machine--to ensure that it runs smoothly. This way if the motor doesn’t run, I know it can only be the motor that is the problem, and not some jam somewhere else in the machine.

Then I get the button controller up on the table. (And obviously, you should not stick your fingers inside the motor housing for any reason!)

Here are the results:



That’s the sound of a potted motor 201 running with no load. Sounds very different than when it’s connected to the rest of the machine, no? Sort of reminds me of a jet engine. I’ll continue running it for a few moments to ensure it runs consistently. And if you’ve inserted new brushes, you ought to run the motor for five minutes or so anyway, to wear the brushes in.

Warning #1: If you run the motor as I’ve done in the video above but it sounds different--for example, if it buzzes first and starts haltingly--STOP and unplug the motor immediately.

Warning #2: If you run the motor for a few minutes and it gets warm, that’s fine, particularly if you’ve been running it full tilt. But if it gets HOT, please STOP and unplug the motor immediately.

Both of those warnings are signs that something is wrong with your motor, either in the field core, the windings or the armature itself. And that something might be dangerous, which is why we ought to unplug the machine immediately. Sadly, those problems are currently beyond the scope of this blog.

But hopefully, everthing has turned out fine.

Re-attaching the Handwheel

It’s my habit to unplug the motor when I re-attach the handwheel, though strictly speaking it’s probably not necessary.

The next thing I do is use the grease syringe to dab some droplets of grease around the perimeter of the fiber gear. People often over-grease these things, but you really don’t need to go nuts with it.

Then I put a single drop of oil on the shaft.

Next I slide the handwheel on.

Replace the washer.

Then screw the stop-motion wheel in, all the way.

Don’t forget to tighten the set screw.

That’s it! Congratulations and enjoy your machine!

Back in business.