First industrial sewing machine

[Kawakneurder]

17 hours ago, dikman said:

The servo you have looks to be a pretty generic type so if you can find instructions for similar machines it might help? I fitted a "generic" servo to a Singer, small pulley on the motor, large pulley to replace the handwheel and a home-made pulley reducer - I got one stitch every 3 seconds! That is a bit extreme, of course, but shows what can be done. If you want slow speed control a speed reducer is a must, and will be cheaper than a Ho Hsing motor.

Hmm yeah I think I should reconsider a different servo. The noise this one makes might be annoying, but its not as bad as a 200 euro extra investment

First I am gonna wait for the smaller pulley, see if that helps a bit, and if its not sufficient I might try to find a speed reducer somewhere.

7 hours ago, CowboyBob said:

Do you know what might be the reason to instead opt for 135x17 needles? Are they more common/cheaper than 134-35? Yes,the 135x17 are easier to get .Another reason to go to a longer needle is with the slight rise of the needlebar will allow you to sew thicker before the needlebar hits the foot.

That actually makes a lot of sense, thanks for the heads up. Although I don't plan on sewing super thick materials, I guess the only advantage for me would be they are easier to find.

 

 

Sadly I have ran into some other issues with the machine though. I started a first project with the machine today, and after finishing a bobbin I wanted to wind a new one. To do this, I put the machine in the highest speed (4500rpm) but I noticed it couldn't even reach 1000 RPM. It also sounded like it was struggling and not very smooth, and the motor was very hot. Turning the handwheel confirmed what i suspected, and that is an extreme increase in friction. Normally if you  would turn the handwheel without motor belt attached, it should keep spinning a bit right? It does not at all, and is actually hard to turn. I detached the pulley that connects the upper assembly shaft to the lower assembly (sorry, don't know the proper terminology) and it still felt similar. I also detached the hand crank wheel/pulley, to see if that was the issue, and it is not. Also the bearing on that end spins smoothly.

This at least isolates the issue to somewhere in the upper part of the machine where there is a significant increase in friction. Are there any components with these 267s that are known to cause increased friction with time?

Edit: I have found that actually nowhere in the cycle does the machine release the tension on the thread (which I already noticed during sewing, but thought this was somewhat normal). I have cleaned the tension assembly, and that seems to work well, and is actuated through a rod that goes to the backside of the machine. Maybe this is related to this issue. I am still analyzing the parts list to figure out how this works. (Parts list can be found here if you want to brainstorm together with me).

Never mind the above, when lifting the foot it does depress the shaft, it just doesn't depress it deeply enough to fully release the tension it seems.

Edited July 11, 2021 by Kawakneurder

[Kawakneurder]

A little update, I have found the part that caused the hang! There is a cam system that moves the middle foot (I believe it is called the 'feeding foot', with the outside being the 'presser foot'). This cam system has apparently 4 points of adjustment:

1. Position of a cam attached to the mainshaft
2. fixation of a cam on the rear
3. Bolt 1 on a small rear axle, on the side of the cam to the main shaft
4. Bolt 2 on the rear axle, closer to the head

The above pictures are obviously from a few different angles to show all the parts (labeled).

The cam bolt in place 2 has a built in bearing, which was stuck. After taping it out, cleaning it with MEK, relubricating with oil and putting it back it seems very smooth.

Secondly, the cam mechanism of 1 also was stuck, and I figured that out by touch after running it a bit . The friction managed to make it upwards of 70 degrees according to my infrared thermo. I managed to pry the two pieces of the cam apart, I tried my best to clean them, but it is a bit annoying to do as you cannot get them off the axle without taking apart the entire machine. However, even after some cleaning they are still binding up. Is it screwed? I thought it shouldn't be *too* damaged, as there are no heat marks on it, although I had been sewing with it for a while. Also it does have some wear marks. But you'd imagine, the more things wear the looser the tolerances get. Anyone have some ideas? I thought maybe using some very high grid wet sand paper (2000 grid or so) to smooth out any superficial damage on there, but i am afraid of damaging the oil seal it has.

 

What is left after that, is figure out how each of these bolts affect the timing/height of the feeding foot and what the adjustment procedure is. I have found a Service manual and I am currently digging through this, but if someone knows how to do this, or has a better resource, advice is always welcome.

So far, I have found this older manual which details the timing procedure for cam 1. Somewhere else on the forum I have read that generally 2 sets the height of the presser feet, and most people leave it in the upmost position. It is a bit vague on how to adjust 3 and 4 though.

Edited July 11, 2021 by Kawakneurder
More info on adjusting timing/raising of feet

[Gymnast]

I am sorry to see these marks on one of the inner surfaces of your bearing. It looks like the machine have been used a long time with no lubrication there. If you got this machine from a qualified dealer, I would contact him about this. I think it can be hard to repair. I hope someone in forum might help you evaluating this further.

Regarding the slow speed control of sewing machines, you can find this issue debated in several threads in this forum. This is the latest two I can remember:

 

[Kawakneurder]

Thanks for the reply Gymnast, I appreciate it.

2 minutes ago, Gymnast said:

I am sorry to see these marks on one of the inner surfaces of your bearing. It looks like the machine have been used a long time with no lubrication there. If you got this machine from a qualified dealer, I would contact him about this. I think it can be hard to repair. I hope someone in forum might help you evaluating this further.

That is indeed what I suspected, what a bummer. Luckily I live in a country which has clear laws that dictate that he should either fully refund me, including shipping, or repair it fully at his costs. Of course he seems to be struggling about this, but in the end I hope I can get something satisfactory. Of course he tries to bring up it is second hand, and that maybe I treated it wrong, but I think the machine should have ran for a long time without lubrication for this to happen, and I lubricated the machine before using it when I got it, so seems like it is his responsibility regardless.

Alternatively I suggested to him to refund a (large) part of what I paid him, and let me fix it myself, although I have found that these two parts are pretty hard to find.

 

5 minutes ago, Gymnast said:

Regarding the slow speed control of sewing machines, you can find this issue debated in several threads in this forum. This is the latest two I can remember:

 

Thanks for the references, I will read through them. On a quick skim it does seem that there's two ways of doing it:

• Cheap/shitty servo or clutch motor + Speed reducer + smaller pulley
• Good servo with control to low RPMs

When the problem about the bearing is solved, I will delve further into this, as at least I can use the machine whilst trying to find a solution for more control. There's a good chance he will have to fully refund me and take back the machine, in which case I will look for another machine and ensure it is working flawlessly before purchasing it...

[Gymnast]

I wish your luck in regarding your communication with the seller of the machine.

I have got several vintage sewing machines, but not from dealers. One of the first things I do is to remove the driving belt to the machine or some motor driving it. In this way you can feel how easy the machine turn. I is quite normal, that a machine can be completely stuck or got high frictions. But after lubricating all the right places and operating the machine by hand (there is youtube videos about this) the machine will normally free up and run smoothly. Then I start to use the motor. With your case bearing I would think I had noticed that something was wrong in this process.

[Kawakneurder]

On 7/14/2021 at 3:50 PM, Gymnast said:

One of the first things I do is to remove the driving belt to the machine or some motor driving it. In this way you can feel how easy the machine turn. I is quite normal, that a machine can be completely stuck or got high frictions. ..... Then I start to use the motor. With your case bearing I would think I had noticed that something was wrong in this process.

I think you are definitely correct about this. And it is definitely a test that I will do in the future with other machines. I am sure I would have picked up on it. When disconnecting the bearing it is now very obvious that the machine turns much, much smoother.

Some positive news though, after a (very long and arduous) negotiation with the seller he has agreed to pay back 450 euro, and I will fix the unit myself. I have already ordered the two replacement parts that have been damaged. If I manage to repair it by just replacing these parts, then I have picked the machine up for quite a good price.

[Gymnast]

It is nice to know, that this shaft most likely is the only problem, and you can get spare parts to fix it. Furthermore, It is good, that you could reach an agreement with the seller. Thank you for the update.