New to this 31K20 and to everything else too

[Tride]

Hi, just joined the forum because most of my google searches about the machine I just picked up led to here....

Background: I know nothing. Like seriously, nothing..... I've never sewn anything in my life, either by hand or machine. 

I actually went down this road because I lent out a hang gliding harness that was never returned, and hard to replace, so I thought, "maybe I could just figure out how to make one". Had literally no idea that you couldn't sew stuff like nylon webbing on any sewing machine. Luckily the first guy that I went to buy a used machine from told me that I needed to look for something a bit more industrial, so I did that, and found someone selling this singer 31K20. They said it could also be used for sewing leather, which I though sounded like a super cool thing to do as well.

So, off I go…. got the thing home, plugged in the super sketchy looking old cloth wrapped power cord, rigged the belt to the wheel, did a 2 minute google search on “how to use a sewing machine" and tried to sew some webbing and padding together. there were a couple stitches, a lot of noise, a lot of me wrestling and tugging, and then the needle broke. Pretty classic new idiot move, I reckon. There were some other needles in the drawer, so i put one of those in, but had no success picking up the lower thread anymore.

 

Finally realized I was being a huge idiot just jumping into it without trying to care for this thing a bit first. So I pulled it off the table and started taking the easy to access stuff apart and cleaning 96 years of gunk off. Haven’t gotten super deep into it yet but I’m amazed at how nicely these parts shine up.

 

So, this is where I am at now, partially disassembled, cleaning what I can, and trying to be a bit smarter about how I proceed. Seems like you guys over here are super knowledgable, so I wanted to throw a few questions to y’all….

 

A- The needle that was in the machine (the one that I broke), had a flat side to the part that mounts in the needle holder, but these spare needles that were in the drawer are all round, with no flat side. Guessing that might have something to do with why they didn't work? I had no idea the world of needles was so complicated…. Found in the paperwork that they gave me with the machine that I’m supposed to use “16x87” needles, but those seem pretty rare, are there any more commonly available needle systems that would fit/work? 

 

B- The motor/clutch system makes a hell of a noise when I start it, but just for a second  then seems to spin fairly normally, (still a bit noisy though). I’m not sure about diving into it myself, guessing my best bet is find someone who knows how to service a 96 year old electric motor and ask them to give it a check out, and maybe new wiring?

 

C - Now that I’m in the “take apart and clean” phase, I’ve been using wd-40 and kerosene and scotchbrite pads and some small brushes. It all seems to be getting me somewhere, but thought maybe you guys have some better tricks/ideas.

 

I’ll try and attach a bunch of photos, good to be here, and stoked for any advice people have for me.

 

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Hmm, guess the photos didn't happen, trying again....

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[JJN]

You have a steep learning curve ahead of you, but don't be intimidated. Take it one step at a time. I'll start the conversation with my first observations. This is what I would do if I came across this machine myself and wanted to sew with it.

Oil oil oil oil oil! That head is bone dry. I never even turn over a machine that was left un-maintained without oiling all the critical points. You will see some oil locations indicated on the top of the machine but download a manual and learn the lubrication routine.

Don't take it apart and don't loosen any screws unless you absolutely know what you are doing. You could be creating more problems, not solving them.

Either re-wire that motor or much better, get a new servo motor for about $150. Trust me, it will be one of the best investment you can make for that machine.

Needles: The needle that you broke sounds like it was a domestic sewing machine needle. Industrial sewing machine needles do not have flats on the shank. The best idea it to use a slightly different needle system from the one that machine was originally set up with. Understand that there are needle systems and within that system there are different needle sizes to choose based of the thread you are using and the material you are sewing. I would adjust the needle bar to use system 135x17 for fabric and 135x16 for leather. If using #69 bonded nylon thread, I would use a size #18 needle.

These needles have a long groove down one side and a scarf, or cutout above the eyelet on the other. The scarf side needs to face bobbin or hook side. If the needle is turned the wrong way, it won't form the loop correctly and the hook will not catch it. It won't stitch.

I usually clean the mechanism with denatured alcohol and an old tooth brush, rags, q-tips and whatever I need to get into the tight spots. Get some 'lily white' sewing machine oil and lubricate all turning or sliding parts. Do not remove any felt or cloth pads or cords you find in the machine. Oil them well as they are used to carry oil to remote locations.

Study the manual for this machine carefully and then check the timing of the needle, hook and feed dog.

Oh, did I mention oil?

Edited November 1, 2020 by JJN

[Tride]

1 hour ago, JJN said:

You have a steep learning curve ahead of you, but don't be intimidated. Take it one step at a time. I'll start the conversation with my first observations. This is what I would do if I came across this machine myself and wanted to sew with it.

Oil oil oil oil oil! That head is bone dry. I never even turn over a machine that was left un-maintained without oiling all the critical points. You will see some oil locations indicated on the top of the machine but download a manual and learn the lubrication routine.

Don't take it apart and don't loosen any screws unless you absolutely know what you are doing. You could be creating more problems, not solving them.

Either re-wire that motor or much better, get a new servo motor for about $150. Trust me, it will be one of the best investment you can make for that machine.

Needles: The needle that you broke sounds like it was a domestic sewing machine needle. Industrial sewing machine needles do not have flats on the shank. The best idea it to use a slightly different needle system from the one that machine was originally set up with. Understand that there are needle systems and within that system there are different needle sizes to choose based of the thread you are using and the material you are sewing. I would adjust the needle bar to use system 135x17 for fabric and 135x16 for leather. If using #69 bonded nylon thread, I would use a size #18 needle.

These needles have a long groove down one side and a scarf, or cutout above the eyelet on the other. The scarf side needs to face bobbin or hook side. If the needle is turned the wrong way, it won't form the loop correctly and the hook will not catch it. It won't stitch.

I usually clean the mechanism with denatured alcohol and an old tooth brush, rags, q-tips and whatever I need to get into the tight spots. Get some 'lily white' sewing machine oil and lubricate all turning or sliding parts. Do not remove any felt or cloth pads or cords you find in the machine. Oil them well as they are used to carry oil to remove locations.

Study the manual for this machine carefully and then check the timing of the needle, hook and feed dog.

Oh, did I mention oil?

Hi JJN, thanks a lot man, appreciate the insight! Yeah I'm already feeling bad about turning it on and trying to sew with it right out of the gate like that..... Breaking the needle was probably a real good thing, as it forced me to slow down....

Oh yeah, and regarding the needle thing, are domestic needles shorter than industrial? I found the tip that broke off, and when I put it together to compare, it looked like it was a shorter overall needle than the spares that were in the drawer, which, I would assume would explain things not lining up and catching if the shorter one were what it was adjusted for.... But then again, there may be another fragment of it somewhere that I didn't see.  In case it helps, here's a photo of the two packs of spare needles that were in the table drawer, and the needle that broke.... Let me know if you think I should be able to get either of these spare models working... Thanks again!

[dikman]

Here's a copy of the user manual to start with - https://www.manualslib.com/manual/1005412/Singer-Class-31k.html

If it works with a domestic needle then it's likely that the needle bar has been re-adjusted and will need to be reset.  You need to check the adjustments and timing of the needle and hook. As JJN said if you can set it to work with 135 needles then it will make life easier as they are a very common type. And in my opinion get rid of the old motor, it belongs in a museum as given its age the wiring insulation is likely to be brittle and cracking so potentially dangerous. A servo motor will make sewing much easier.

There are guys on here who sew the sort of stuff you're talking about and hopefully they will chime in.

 

[Tride]

22 minutes ago, dikman said:

Here's a copy of the user manual to start with - https://www.manualslib.com/manual/1005412/Singer-Class-31k.html

If it works with a domestic needle then it's likely that the needle bar has been re-adjusted and will need to be reset.  You need to check the adjustments and timing of the needle and hook. As JJN said if you can set it to work with 135 needles then it will make life easier as they are a very common type. And in my opinion get rid of the old motor, it belongs in a museum as given its age the wiring insulation is likely to be brittle and cracking so potentially dangerous. A servo motor will make sewing much easier.

There are guys on here who sew the sort of stuff you're talking about and hopefully they will chime in.

 

Right on, thanks for the advice. Knowing absolutely nothing about servo motors, what kind of things would I want to factor in when looking for the appropriate one?

 

[JJN]

Servo motor: This is what I use and recommend.

https://www.tolindsewmach.com/motors.html

This vendor is a contributor and financial supporter of this forum. There are others here too. You can find them in the ads at the top of each page. They make this forum possible and suggest giving them your business.

John

[Wizcrafts]

3 hours ago, Tride said:

Right on, thanks for the advice. Knowing absolutely nothing about servo motors, what kind of things would I want to factor in when looking for the appropriate one?

There are basically two types of servo motor. One has brushes, like a regular clutch motor has. The other is an electronic brushless motor. The motors with brushes usually have a simple rotary switch or potentiometer to limit the top speed. The brushless types usual;ly have push buttons with multiple functions and are complicated to setup. The dial type motors usually start at zero, with less torque, then gradually speed up with foot motion. The pushbutton controlled motors usually start at 200 or 300 rpm, with good torque, then increase to the preset maximum.

I have had both types and will probably never ever use a brushless pushbutton motor again. I have added 3:1 speed reducers/torque multipliers to the servo motors where I need lots of torque at very slow startup speeds. I have four of the Family Sew FS-550s motors mentioned by JJN. There are box style and free standing reducers listed on the same page.

[charliegamer007]

As I'm just starting out with my first  machine  I just bought the CONSEW CSM550-1 and I'm hoping I made a good choice

[Wizcrafts]

7 minutes ago, charliegamer007 said:

As I'm just starting out with my first  machine  I just bought the CONSEW CSM550-1 and I'm hoping I made a good choice

This motor looks good according to the specs. It also has a speed dial. However, it appears that it ships with a 75mm pulley. That is too fast for a leather sewing machine. The motors I get from Toledo Industrial have 50mm pulleys that give more low speed torque.

[charliegamer007]

6 minutes ago, Wizcrafts said:

That is too fast for a leather sewing machine

I set it on lowest setting and I did notice it wants to take off. Toledo you say!  will do some digging into this thanks just need to wait for more cash now.

[Wizcrafts]

1 hour ago, charliegamer007 said:

I set it on lowest setting and I did notice it wants to take off. Toledo you say!  will do some digging into this thanks just need to wait for more cash now.

They may be able to sell you a small pulley and shorter v-belt. You will probably have to mic the diameter of the output shaft. Call them at: 866-362-7397, or use the website's contact form.

[charliegamer007]

Thank you

[sandmanred]

I have a 31-15 and think it's great.  There's tons of them out there and you can still get most of the parts you'd ever need.

I don't think you'll get a 135x17 to run as it's probably too long.  I didn't try but I did a quick length comparison I think by the time you get the eye where you need it for hook timing you'll be crashing the needle clamp into the body at the top of the needle stroke.  Here's a picture of the needles I run below. They are cheap and readily available on ebay.  A suffix of LR indicates for leather.

I don't see a bobbin case or bobbins in your pics.  I think it's a class 15.  You should be able to get from ebay pretty easy.  You just have to watch the little arm that comes off the case to keep from spinning, I had to trim mine shorter for it to fit.

If it was heavily used you'll probably have to replace the hook and the little pin you will find inside the tension assembly.  If worn the hook won't run smooth, you'll be able to tell by the sound.  Also check it for any burrs or sharp edges where the thread slides on it.  The new ones I got on ebay have both needed some filing on the end opposite the hook to get them to fit.  There needs to be a little play between the hook and hook driver to let the top thread pass.  The little pin in the center of the tension assembly pushes the outer disc out a bit when the presser foot is up.  They get shorter with wear and stop working all together when worn too.  If your tension stays high when you lift the presser check this first.

I also agree on getting the smaller pulley on the motor,  I run a 45 or 55 mm drive pulley.  I also added a pulley the fits over the stock handwheel that increases the diameter to about 5.5 inches.  That gets me down to as low as about 1 stitch per second.

Edited November 2, 2020 by sandmanred
add comment about leather needles

[Tride]

Thanks so much for all the responses, very glad to be here and learning from y'all.

[DonInReno]

30 years ago a 31-20 was the first industrial machine I learned to use...it’s basic and simple in every way.   I currently have another 31-20 and it sews 138 quite well.

You can’t put any old random needle in any sewing machine and expect it to work.   Don’t take anything apart or turn any screw until you know what it does.   Industrials don’t need to be taken apart for general cleaning.

I suggest you upgrade that motor - it will only make learning to sew more difficult.

Edited November 3, 2020 by DonInReno

[Tride]

Update(s)....

First, thanks again for all the input. Learning a lot.

So after watching some youtube on adjusting timing, and looking at this machine, it looks like it was definitely adjusted for a shorter needle than these industrial ones that came in the drawer. So, thought I'd try adjusting needle height, didn't look to complicated...... But.... I'm stalled because after removing the screw in the needle bar clamp, the needle bar still won't move, just seems seized in there. Don't want to wrestle it too hard and wreck something, so I'm just giving it periodic seafoam squirts and hoping that helps loosen it up. Thought about blocking the top or bottom of the needle bar so it can't move and then applying pressure by trying to turn the hand wheel, but again that seems pretty aggressive so not sure it's best call.

One other thing I've noticed while in there, is the tension release lever (part #43944) seems just a hair off, so when lifting the presser foot, the pointy part of that grazes the pin and slides off to the side, instead of pushing it in. I suppose I could try removing the lever and giving it the slightest of bends to try and line it up better, but again, feels a bit aggressive....I'll try attaching a video of that issue...

 

 

[sandmanred]

It might have been my 31-15 or another machine but  I've had a needle bar scarred up too and resist moving after the set screw is loose.  I recall doing something along these lines, put a soft metal spacer between the body where the set screw goes and the casting below, then tapping on the top of the needle bar.  I still didn't hit it very hard but once loose I was able to extract it out the top and file the burrs back to smooth.  The spacer transfers the tapping force to a beefier part of the body and keeps any forces off the linkage connected to the needle bar but still go gently!

 

 

[Tride]

3 hours ago, sandmanred said:

It might have been my 31-15 or another machine but  I've had a needle bar scarred up too and resist moving after the set screw is loose.  I recall doing something along these lines, put a soft metal spacer between the body where the set screw goes and the casting below, then tapping on the top of the needle bar.  I still didn't hit it very hard but once loose I was able to extract it out the top and file the burrs back to smooth.  The spacer transfers the tapping force to a beefier part of the body and keeps any forces off the linkage connected to the needle bar but still go gently!

 

 

Yes! Good thinking, and happy to report it worked! (I used a plastic block). Thanks!

Now that I freed up the needle bar I removed it and cleaned it up with some wd-40 and a scotchbrite pad, it's looking like new again and slides freely through the adjuster piece.

I then tried to set the needle height as best I could to try and accommodate the needles that I have, which are labeled : "DPx35LR  134x35LR  SY7227 130/19"  

For a minute it looked like it might not work, as it seems like these needles are just a tiny bit too long. My initial attempt, setting the height with the needle tip sitting just under the hook, looked good but then when I tried turning it through a complete cycle the needle holder hit the body of the machine at the top of the stroke. So I moved to what seems to be the maximum distance that still allows a complete turn cycle, which set the eye of the needle a bit further under the hook than the recommended 3/32 distance, but, on trying it out with a slow speed hand turn.... was successful in hooking the thread!

Guessing maybe this is the absolute maximum length needle that could work. Will look into all the other needle system options that everyone has been recommending, feel like getting a tiny bit more tolerance is probably a good call.

[sandmanred]

Great!

My needle bar might be a tad low by that 3/32 standard but there's plenty of clearance to the body on top at the top of stroke running the needles I pictured in the post above.