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Reconditioning a Singer 15-30 - Part 3: Reassembly

Posted by James Wolfensberger on

If you are just now joining this tutorial series, you may wish to read:

Having completed the cleaning steps in Part 2, I'm now going to reassemble my 1920 Singer model 15-30.

If you have a different model 15, like the 15-90 or 15-91, the steps here are still generally applicable and can be helpful. However, your bobbin winder, tensioner, and some other assemblies will be comprised of different parts while being functionally similar to my 15-30. I will include links that could be helpful to owners of different 15 models.

Presser Bar

Here are the parts we'll use to reassemble the presser bar and its related pieces:

Place the presser bar guide into place, then slide the presser bar down through the hole on top of the face of your machine, through the guide and through the exit hole at the bottom of the face area. Install the screw that holds the bar into place, barely tightening the screw so that it holds the bar in place, but not tightly.

Install the presser bar lifter with the single screw which holds it into place.

Drop the presser bar spring down through the top hole:

Drop the washer onto the bar through the top hole:

I recommend putting a drop of Bluecreeper synthetic lubricant or SMO (sewing machine oil) on the threads of the pressure regulator thumb screw, then install it:

At this stage, the presser bar is not adjusted to the correct position, and the screw holding the bar into the guide is not fully tightened. Allow this to remain as is while we proceed. We will install the thread cutter later as well.

The Race Assembly

We will use these parts to install the race assembly in the shuttle and hook area:

Follow these images to rebuild the race assembly of a 15-30:

When you replace the shuttle race cap (below), do not fully tighten the first screw you insert. Just start the threads loosely to hold the cap into place while you start the second screw. This is a technique you should always apply when installing a part with multiple screws holding it into place. Start each screw loosely, then tighten them each in a balanced, alternating manner in an effort to apply comparable torque - or pressure - to each screw. This allows the screws to seat evenly within the holes.

Use the correct screws to mount the race assembly as shown below. I recommend a drop of oil on the threads of each screw. The correct position of the race is a matter of precision. If the screws do not go in smoothly, you may not have the race body aligned properly. Alternate while tightening the screws.

Feed Dogs, Plates & Foot Area

Install the feed dogs. I use a small ratcheting wrench if the screw position is too challenging for a standard screwdriver. Snug them firmly, but without over-tightening in a manner to damage the screw slots.

Install the needle plate. There is no need to apply significant torque to the screws.

Let's not concern ourselves with the bobbin case and bobbin at the moment, but go ahead and replace the slide plate over the bobbin area if you like. I usually do.

Install the thread cutter by sliding it up onto the presser bar. Often these cutters are challenging to get onto the bar. I carefully push them up with a flat-head screwdriver leveraged against a block of wood. Be patient, taking care to not slip and push the screwdriver tip into your hand or the finish of your machine. Even, slow upward pressure while wiggling and turning the cutter will help you guide it into place. You could also cushion the screwdriver tip by wrapping it with cloth.

Install the presser foot using its thumb screw to mount it:

Now that the needle plate is installed, we can adjust the presser bar height. First we'll do our best to get the bar position close, if not entirely correct. Loosen the set screw that holds the presser bar in place within the presser bar guide. Loosen the pressure regulator thumb screw to release all tension from the presser bar. With the presser bar lifter lowered (no upward pressure against the spring) and the feed dogs lower than the needle plate, allow the presser foot to rest lightly against the needle plate. Align the presser foot properly over the feed dog opening by rotating the bar as needed. Tighten the set screw in the presser bar guide so that the presser bar is secured into place. Lastly, tighten the pressure regulator thumb screw to apply a little tension to the presser bar - you will adjust that pressure more precisely when you begin sewing.

More technically accurate, this is from the Singer 15 manual:

With the presser bar lifter raised, there should be a clearance of 19/64 inch between the presser foot and the throat plate. With the presser bar lowered, the presser foot should parallel the feed dog, and the needle should be close to (but not touch) the inner, or right hand, side of the large toe of the presser foot.


In case the presser bar and foot are not set as instructed, remove the face plate and raise the presser bar lifter. Then loosen the presser bar bracket [guide] and raise or lower the presser bar until proper height is obtained; also make sure that the presser foot is parallel with the feed dog and that the needle is close to the inner, or right hand, side of the big toe of the presser foot. Securely tighten [the presser foot bracket/guide screw] and replace the face plate.

Yeah, they actually referenced "19/64 inch." Just do your best and then make minor adjustments when you try sewing after this reassembly is complete.

Install the small wire thread guide and the needle clamp:

Thread Tension Assembly

The tension assembly on my 15-30 is similar to the "old style" tensioners (prior to the numbered "dials") on the Singer models 66 and 99. If your tension assembly is like mine, you can gain more understanding of it by referencing this document called Upper Tension Mechanism. However, please understand that the mechanisms shown in that document do not match my 15-30 precisely, yet the principles are so closely related that they will help you no matter which vintage tensioner you have, and the document includes the more modern "dial" assembly as well.

The model 15 "dial" assembly is well described in this video:

Also, we have an article here that might be helpful:

While my tension assembly is from 1920 and not modernized with a numbered dial, it is nonetheless a well designed mechanism, impressive in its simplicity and reliability.

Notice below that my tension stud has a slot:

The slot in the tension stud is where the tab on the thread take up spring will rest so that the spring creates tension rather than spinning around the rod:

Notice that the tension release pin is to be inserted into the tension stud:

Mount the face plate on your machine. Place the tension assembly "barrel" into the face plate and install the two screws (see below). The smaller set screw (#1) is the mounting screw that will hold the stud into place. The other screw (#2) is to allow adjustment. Below, I've already inserted the tension rod into place. Before tightening #1, I rotated the tension rod clockwise in order to establish the tension on the spring, then I fully tightened #1.

With the tension rod in the correct position, the thread take up spring will return to its position if I press it upward as shown here:

I can now add the remaining parts in the correct order. The tension discs:

The tension release plate:

The "beehive" spring:

And finally, the thumb nut:

The Bobbin Winder

Do you know which closet in your house is most soundproof? That is where you will want to go to scream if you're concerned it will alarm your family. Because if you've never reassembled one of the more complex vintage bobbin winders, not only are you at risk of temporary insanity, you are also likely to decide you hate me for recommending in Part 1 that you take it apart.

Why have I been so cruel? The truth is, I'm trying to help. Call it tough love. Once you grind through this challenge, you have definitely earned a merit badge and are well on your way to proficiency with these classic beauties. You may grumble, curse, scream and even cry a little (I usually do), but you will feel great when you succeed.

There are variations of bobbin winders, and while the one in this tutorial at the Errant Pear blog isn't exactly like mine, the instructions provided so well by Claire could be helpful to you.

Thank goodness that Ray Elkin has been kind enough to make a video on the bobbin winder!

Ray made this a little extra fun by recording the video in a reversed mirror-image perspective, but that's okay - I'm just thankful he was willing to offer this help to all of us in the VSM community:

If you watch Ray's video, then also reference my photos below, you will manage this.

First, I looked at the parts and whimpered. I don't care much for puzzles, which reminds me... why am I the one doing this? My wife could solve a Rubik's cube when she was a kid, and she beat me at chess so many times that I officially retired from the game about 6 years ago (the world of chess did not notice). But Brenda has more important stuff to do, so this is my job.

I placed the small spring into its - what? - I'll call it a chamber, I guess. A tab on the spring fits into a tiny hole at the bottom of the chamber, then the other tab protrudes:

I next attached the pivoting thread guide:

In this photo, you can see the spring tab protruding properly from its hole:

I assembled the cam and gear wheel. The large screw through the center is just resting there for now.

A curved, sort of "domed" washer was next:

I attached the cam and gear wheel to the larger assembly, passing through the washer. A nut goes on the back:

Next I braced myself for frustration. Here is the larger spring with its protruding tab:

The tab will be positioned in this hole:

From this point, I again need to refer you to Ray Elkin's video above. The following steps are difficult to describe and illustrate with photos, because as I accomplished them, I was mostly thinking about how much I hate bobbin winders, especially on a machine that I'm going to fit with a hand crank - as if Brenda will ever hand crank thread onto her bobbin. But we have to do this right and preserve this machine properly. Grrr.

You will know you have your winder assembled correctly when it pivots downward and latches into position properly with the push of a finger, then can be unlatched using the push lever that rests behind the little shaft where you would normally mount a bobbin to be wound with thread. Um, yeah... that translates well, doesn't it? You hate me now.

So again, watch Ray's video above, read Clair's tutorial, look at my photos, and push through it. You can do it. When you struggle, take a break, but don't throw your bobbin winder in the trash.

The Balance Wheel & Cover

You might recall from the previous parts of this series that my machine was originally a manual model, and it had been electrified with a hideous non-Singer motor and light. I totally get why someone post-1920 did that, but Brenda and I are eager to try a hand crank. I will not put the solid balance wheel back on my machine. Instead, I will use a spoked wheel to support a hand crank conversion.

Our friend Janet Szabo, replete with the wry humor and abundant style of a woman who regularly wrestles bears off of her front porch, told me about the hand cranks sold by TreadleLady on Etsy. Janet has tried more than one brand of hand crank conversion kits, and prefers TreadleLady's model. I was pleased that my order from TreadleLady was processed quickly and the merchandise seems solid. Janet's advice was good.

When you place the tabbed stop motion lock washer onto the shaft as shown below, notice the two inner center tabs actually project outward, away from the shaft. Take note of the position of the three outer tabs - since there are three of them, the washer can be rotated to change the position of the tabs. This is important because when you tighten the knob - actually called the stop motion wheel - and then replace the screw, if the stop motion wheel doesn't tighten and loosen properly for clutch control when winding a bobbin or sewing, you may have to rotate the washer so that the tabs change positions, and the set screw that rotates between the tabs has room to accommodate being fully tightened or fully loosened.

Below, my washer tabs sit at the 10 o'clock, 2 o'clock, and 6 o'clock positions. If I determined that this wasn't allowing the clutch to work properly after screwing on the stop motion wheel, inserting the screw, and trying the clutch (tightening and loosening), I could simply remove the stop motion wheel, lift the washer away and rotate it so that the tabs were at 12, 4, and 8 o'clock, then replace the stop motion wheel, the screw, and see how it performs.

Installing the hand crank is incredibly simple following the instructions that were included. I easily bolted mine into place before replacing the balance wheel cover:

I replaced the rear pillar cover plate:

I installed the stitch regulator lever which, on my 15-30, simply screws into position.

Electric Machines

If your machine is electric, remounting an external motor and belt (as well as your light) are relatively easy, but please inspect your wiring thoroughly. You can use the light compound from Part 2 to polish the motor's exterior - just don't allow any compound or polish to enter the motor.

If you have the Singer 15-91 with a potted motor, be sure to read this series of posts at The Vintage Singer Sewing Machine Blog. Even if you do not require an overhaul of your potted motor, the series covers proper lubrication of the potted motor and you'll gain valuable understanding of why your potted motor is awesome.

The exterior of your foot pedal can be cleaned and polished nicely with the light compound as well. If your foot pedal doesn't provide good variable speed control, have a look at this blog article for help disassembling, adjusting, and reassembling a bakelite foot pedal.


Final "Flush" & Lubrication

The Singer 15-91 manual will help you reference the lubrication points on page 36 of the manual (page 20 of the PDF file). This blog article uses a Featherweight as an example, but otherwise explains oiling your vintage machine in excellent detail.

Make sure that all oil holes are free of any compound or residue as a result of polishing during Part 2. I use toothpicks and cotton swabs (dampened with Bluecreeper or SMO) as necessary, trying not to force any gunk further into the machine.

While turning the machine slowly, put a few drops of Bluecreeper lubricant in each oil hole and onto each oiling point. We're going to use this technique to make sure we flush out any debris that has dropped into the internal mechanisms of the machine while we polished it.

Once we have "flushed" all the oiling points with just a little Bluecreeper, we should then lubricate the machine normally using SMO. Dry away any excess lubricant from the bottom of your machine.

Sewing Test & Tuning

If necessary, remount your machine into its treadle or base. Then load a threaded bobbin into the bobbin case, insert the bobbin case, and thread your machine. The manual and YouTube videos can help with threading the machine.

Do a little sewing. If your stitches aren't perfect, you should reference the manual to ensure a variety of adjustments are correct, usually beginning with thread tension and presser foot pressure. Based on our limited disassembly in Part 1, the shuttle timing and needle bar position are not likely culprits but must be considered if the machine isn't operating properly. Both of these are covered in the manual as well.

Clean & Shine the Surface of Your Machine

We polished our machine thoroughly in Part 2, but since then we've handled it extensively as we reassembled it. It's probably smudged and covered with fingerprints. You may be able to buff it nicely with a clean cotton cloth. If your finish isn't in great shape, try coating the black surface with the thinnest, slightest amount of SMO you can manage, then buff the oil no differently than you would buff wax from a car.

I hope this article has been helpful!

If you have a few more minutes and you like to make quilts, have a look at our other blog.

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  • An email has been sent to Rafay with suggestions for the Singer 15 issue :)

    James Wolfensberger on
  • Hello. Thank you for your useful posts. I have an old singer (15k with the sphynx decals) and I have a problem with the timing, I guess. After a few correct stitches, the thread doesn’t make the knot. It’s like the mechanism of the bobbin wouldn’t hook the thread of the needle. I appreciate any kind of suggestions. Thank you very much.

    rafay on

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