Eyeballing a Singer 51

[Calidora]

On 11/10/2024 at 11:01 AM, Constabulary said:

 

As mentioned before ex factory it is using a needle system with fairly thin shafts and you can probably get it to sew with 138 thread if the needle plate has a large enough hole but you most likely you have to convert the needle bar for using a common needle system like 135x16 and you need a new tension unit.  So expect to invest approx $50 or more in it for parts + some tinkering. Maybe new needle plate and feed dog and I´m not sure if the roller foot is ideal for your work. But you can convert that as well.... But it all takes parts, time and tinkering.

What do I need to convert the needle bar?

[Calidora]

Let's try this again 

Nevermind. If it's ok I'll start another post when I have the machine up and running and add more pictures then. 

Edited November 16, 2024 by Calidora
Still no attachments?

[Constabulary]

14 hours ago, Calidora said:

What do I need to convert the needle bar?

basically a new needle bar. Your machine is the 2nd type 51w and needs a 6.35mm needle bar as it was used in the Singer 111w triple feed machines.

Like this one:

https://www.ebay.com/itm/152426180931

But you have to shorten it.

LW member @eddo has done this with his machine too:

 

[Calidora]

8 hours ago, Constabulary said:

basically a new needle bar. Your machine is the 2nd type 51w and needs a 6.35mm needle bar as it was used in the Singer 111w triple feed machines.

Like this one:

https://www.ebay.com/itm/152426180931

But you have to shorten it.

LW member @eddo has done this with his machine too:

 

Thank you. I'll do that. 

[Calidora]

I finally got this machine set up. I was wondering. Did I get it threaded properly?

 

Edited yesterday at 01:26 AM by Northmount
Removed duplicated file

[Wizcrafts]

29 minutes ago, Calidora said:

I finally got this machine set up. I was wondering. Did I get it threaded properly?

First of all, what in the Sam Hill is that thing sticking out the top of the head? I've never seen any pin like that. Somebody added it to the machine.

Second, it appears that you haven't passed the thread through the check spring. You must pull the thread around the tension disks, then feed it through that spring, then up to the take-up lever.

[Calidora]

1 hour ago, Wizcrafts said:

First of all, what in the Sam Hill is that thing sticking out the top of the head? I've never seen any pin like that. Somebody added it to the machine.

Second, it appears that you haven't passed the thread through the check spring. You must pull the thread around the tension disks, then feed it through that spring, then up to the take-up lever.

Yes. I added that. On the manual it showed that it has a pin there but it was missing so I put a bent needle in the hole. It seems to sew better with it than without although now that you mention that it's not going through the spring that might be why. 

[Constabulary]

some Singer machines have a crazy thread path and an "odd" / unnecessary thread loop or hole - don´t know why. My 108w20 also has this path and I do not follow it and it works w/o problem.

Beside that you have not instated the new tension unit correctly therefore the machine will not work properly.

Not much time atm, have to run, more later....

Edited Monday at 06:34 PM by Constabulary

[Calidora]

10 hours ago, Constabulary said:

some Singer machines have a crazy thread path and an "odd" / unnecessary thread loop or hole - don´t know why. My 108w20 also has this path and I do not follow it and it works w/o problem.

Beside that you have not instated the new tension unit correctly therefore the machine will not work properly.

Not much time atm, have to run, more later....

Interesting. I thought I installed it correctly but I'll be the first to admit that I don't know that much about these machines. When you have time let me know how it should be. Thank you. 

[AlZilla]

32 minutes ago, Calidora said:

Interesting. I thought I installed it correctly but I'll be the first to admit that I don't know that much about these machines. When you have time let me know how it should be. Thank you. 

I can get you started. See that round spring pointing straight up on your tension unit? Right at the 12:00 position? It should probably be at about 10:00, straddling the thread. There's some other odd stuff there I won't comment on, but the check spring gets you started.

Edit: I think I see a set screw on the side at 5:00. Should be that  if you loosen it, you can rotate the check spring into position.

[Calidora]

1 hour ago, AlZilla said:

I can get you started. See that round spring pointing straight up on your tension unit? Right at the 12:00 position? It should probably be at about 10:00, straddling the thread. There's some other odd stuff there I won't comment on, but the check spring gets you started.

Edit: I think I see a set screw on the side at 5:00. Should be that  if you loosen it, you can rotate the check spring into position.

More like this then?

[AlZilla]

4 hours ago, Calidora said:

More like this then?

Yep, then the thread would be behind that finger pointing upwards at 11:00.

When everything is working right, you'd pull the thread around the disk and them pull it up until it snaps behind the finger.  Most threading videos for machines with an exposed tension unit will demonstrate it.

On the other side, where the thread enters the tension unit, it ought to be straighter and more taut, but it may just be loosely strung around there in the pic.

Making headway.

EDIT: Right at about 2 minutes of this video, Randy Your Sewing Machine Man demonstrates it nicely:

 

[Constabulary]

The check spring should rest in ~ the 9 o'clock position. There is a curved metal piece (A) underneath the tension unit that is secured by a screw (B). The end where the check spring rests on should be at approx 9 o'clock and the check spring needs a little pretension so when the thread lever goes down the spring goes back on the rest.

Edited Tuesday at 12:30 PM by Constabulary

[Calidora]

7 hours ago, Constabulary said:

The check spring should rest in ~ the 9 o'clock position. There is a curved metal piece (A) underneath the tension unit that is secured by a screw (B). The end where the check spring rests on should be at approx 9 o'clock and the check spring needs a little pretension so when the thread lever goes down the spring goes back on the rest.

Ok cool Makes sense. When I get home from work I'll do that. 

[Calidora]

On 6/24/2025 at 4:49 AM, Constabulary said:

The check spring should rest in ~ the 9 o'clock position. There is a curved metal piece (A) underneath the tension unit that is secured by a screw (B). The end where the check spring rests on should be at approx 9 o'clock and the check spring needs a little pretension so when the thread lever goes down the spring goes back on the rest.

So, like this?

[Constabulary]

looks good so far - how ever some fine tuning could be necessary. Little hint - the thread should run above the thread lever and not under it.