Singer 31-15 Stitch Issues

[MAlexanderConcepts]

Hello everyone, I am the new owner of a Singer 31-15 and I am having some troubles with my stitches. I have played with the tensions, and adjusted the timing. At first, it would not catch the stitches at all, and when it would, the top stitch would get sheared away. This is shown in the final two pictures in the link.

 After I adjusted the timing, the shearing ceased, and some stitches would set, but only the first few. Other problems I am having are the stitches may stitch, it skips several stitches, then will resume. I have included Imgur links of my pictures of my leather pieces and stitching I am using to set this up because the files are too large. This is shown in the first 3 images.

https://imgur.com/a/q4IW47E

I'm using Tex-90 thread, and a size 18 Schmetz universal needle. I think that may be part of the problem,  so I ordered some Organ 31-15 size 20 leather needles as well.

Edited May 29, 2018 by MAlexanderConcepts

[Wizcrafts]

The Singer 31-15 is a tailoring machine. Unless it is a later model, you're pushing the machine's limit to use T90 thread (depends on the shuttle and springs). In any event, I use at least a #19 needle when sewing leather with T90 thread. Always use a leather point needle with leather. Always use a round point/standard needle with cloth, vinyl and webbing.

Know that the tension and check springs are weak compared to walking foot machine springs. This means you'll need more top and less bobbin tension to balance the knots.

You can play around with the throw and tension of the check spring to get the best achievable results with your machine. A longer throw up and down holds the thread taut longer during the downstroke cycle. This may help to tighten and stabilize the top thread as the needle approaches the bottom of its travel. But, it must have stopped moving down before the needle starts back up or the loop will dissolve before it can be picked off by the hook.

[MAlexanderConcepts]

6 minutes ago, Wizcrafts said:

The Singer 31-15 is a tailoring machine. Unless it is a later model, you're pushing the machine's limit to use T90 thread (depends on the shuttle and springs). In any event, I use at least a #19 needle when sewing leather with T90 thread. Always use a leather point needle with leather. Always use a round point/standard needle with cloth, vinyl and webbing.

Know that the tension and check springs are weak compared to walking foot machine springs. This means you'll need more top and less bobbin tension to balance the knots.

You can play around with the throw and tension of the check spring to get the best achievable results with your machine. A longer throw up and down holds the thread taut longer during the downstroke cycle. This may help to tighten and stabilize the top thread as the needle approaches the bottom of its travel. But, it must have stopped moving down before the needle starts back up or the loop will dissolve before it can be picked off by the hook.

thank you very much for the reply. Can you please explain what throw is? I am new to this so some of the terms you are using do not register with me.

Furthermore, what are the specific adjustments I should be making? I know you have made recommendations, but again, as someone who is new to this, it does not completely register.

Thank you

[Wizcrafts]

Sorry, I have work to do in my own shop. Maybe somebody else can help you out.

[RockyAussie]

7 hours ago, MAlexanderConcepts said:

thank you very much for the reply. Can you please explain what throw is? I am new to this so some of the terms you are using do not register with me.

Furthermore, what are the specific adjustments I should be making? I know you have made recommendations, but again, as someone who is new to this, it does not completely register.

Thank you

This manual mentioned in this post may help -  The second link shows a tension check spring and this can be adjusted to be tighter or looser and the throw means the distance that this spring can move. This distance is normally set to let the thread to start going slack just as the needle is about to enter the leather. As Wiz said I would try a bigger needle and make sure it is facing the right way as often if the needle is wrongly orientated it will miss stitch and I think we have all been guilty of putting the needle in with the slot facing the wrong way more than we would care to admit.

https://www.singeronline.com/3115.html

[MAlexanderConcepts]

4 hours ago, RockyAussie said:

This manual mentioned in this post may help -  The second link shows a tension check spring and this can be adjusted to be tighter or looser and the throw means the distance that this spring can move. This distance is normally set to let the thread to start going slack just as the needle is about to enter the leather. As Wiz said I would try a bigger needle and make sure it is facing the right way as often if the needle is wrongly orientated it will miss stitch and I think we have all been guilty of putting the needle in with the slot facing the wrong way more than we would care to admit.

https://www.singeronline.com/3115.html

Thank you so much. When my needles come in, I will use this to help me and see if my situation can be resolved. Very much appreciated!