Singer 31K15

[maaryan08]

Hi everyone ,

I am new on this forum , and i'm asking for you're help . I have some problems with my singer 31-15 , the underneath thread is hanging or i don't know how is possible to tangle in this way . I notice that sometie the hooked thread didn't get over the bobin , and that may be the cause of this , but i need some of your suggestion . i have attached a picture of thread. Sorry for my english.

[Wizcrafts]

I had a similar problem with my 1920 Singer 31-15. The top thread would occasionally get picked up too late in the oscillation cycle, preventing it from going around the bobbin. My solution was to advance the timing of the hook, which was done at the far right side of the machine, with the head tilted back on the table. There is an eccentric screw and finger driving the shuttle driver shaft. You have to loosen the nut, adjust the hook forward a bit, lock it down and test for results. These adjustments may also require the needle bar to be repositioned to get the hook above the eye at the right moment and position.

[maaryan08]

I had a similar problem with my 1920 Singer 31-15. The top thread would occasionally get picked up too late in the oscillation cycle, preventing it from going around the bobbin. My solution was to advance the timing of the hook, which was done at the far right side of the machine, with the head tilted back on the table. There is an eccentric screw and finger driving the shuttle driver shaft. You have to loosen the nut, adjust the hook forward a bit, lock it down and test for results. These adjustments may also require the needle bar to be repositioned to get the hook above the eye at the right moment and position.

I was thinking about this , but i wasn't convinced that may the problem . Thank you for the advice , i will return with results .

[maaryan08]

I didn't succed to repair it , the thread is picking up too late , but how i can put this in order ? I have adjustet the hook from lef side , the side where is the bobbin , but no results , i dont understand where are you saying to advance the timing from right side ?

Edited October 16, 2013 by maaryan08

[maaryan08]

I uploaded this picure to see from where i advanced the hook timing . Thank you again.

[Wizcrafts]

On my 31-15 there is a solid steel pin securing the shuttle driver to the shaft. I had to adjust the hook timing on the right side where the shaft from the top is joined to the shuttle driver shaft, which are visible in your photo.

After advancing the hook, check the position of the point in relation to the ascending needle's eye. The needle must move enough to form a decent loop on the right of the eye. The hook must pass above the eye, somewhere within the cutout scarf area, then grab the loop. Watch this happen with the throat plate off. It may give a clue as to what is or is not happening.

The clearance between the shuttle driver and shuttle makes a difference. Too much slack allows the shuttle and bobbin to self-retard under load. Too little and the top thread gets pinched as it goes around the assembly.

[Wizcrafts]

Check the lateral clearance between the right side of the needle and the point of the hook. They should be close, but not touch.

[maaryan08]

The hook point and the needle are colse enough , the thread loop is good and the hooking its good , but it's seems to have a delay . After the hook grab the tread and take it to the ending position the thread is not retriving to get over the bobin , and is going back . I don't understand where could be the problem .

[Wizcrafts]

The hook point and the needle are colse enough , the thread loop is good and the hooking its good , but it's seems to have a delay . After the hook grab the tread and take it to the ending position the thread is not retriving to get over the bobin , and is going back . I don't understand where could be the problem .

I had to fix the same problem on my machine. After advancing the hook and positioning it properly over the eye, I noticed that there was a lot of slack between the shuttle driver and shuttle. This slack allowed the shuttle to back up as the hook grabbed the loop. I had created that extra space to get my replacement shuttle to fit without jamming and overdid it. If your shuttle has too much forward-backward slack, the shuttle will pull back like mine did. The only way I found to correct this was to use a vise-grip and carefully bent the shuttle driver outwards. Only a slight movement is necessary to take up this slack. If your driver is removable, you might try replacing it instead of bending it. Hopefully, your shuttle driver is not steel-pinned on like mine is.

Note: moving the driver in or out changes its lateral relationship to the needle. The driver has a slightly tapered area that helps to push the loop up and to the right, as the needle ascends. Moving the driver outward may cause it to hit the needle and push it to the left. Moving it inward may leave more space than is ideal. So, if you have to bend the driver to reduce slack in the shuttle, you may also have to reposition the driver sideways.

These are really old design machines.

[maaryan08]

The driver is removable . is very difficult beacause the space that will remain betwin neddle and hook if i bend the driver . I don't really have where to buy replecement pars for this machine in my country . I'm thinking if i bend the driver like you said , the thread it will get over easily over the bobbin ?

[Wizcrafts]

Take up some of the slack, but leave just enough for the top thread to go all the way around the shuttle, without getting squeezed at the back by the driver. You need some slack, but not so much as to allow the shuttle to back up significantly as it picks up the thread loop. That fall back retards the timing.

Don't lock the jaws of the vise grip onto the ends, Clamp in the middle, where the top thread is less likely to be present. While you have clear access to the driver, use Emory cloth to smooth and polish the tapered/radiused end where the top thread exits.

[Slow Learner]

Slightly off topic but I have been trying to use my 31 15 and it keeps breaking the top thread when sewing leather. Fabric works fine. Also would a servo motor help slow down the machine for more control in tighter sewing situations. I would love to be able to use this machine to put decorative stitches on belts, wallets and watch bands.

[cariocastyle]

Hello,

I have exactly the same timing probleme on my 31 K 15. I would like to ask Wizcrafts where is exactly the eccentric screw and nut that needs to be loosen in order to adjust the position of the hook ?

Here is a picture, where is the screw? A or B or somewhere else ?

I would also like to add that the hook only fail to pick up the top thread when I have two layers of quite thick fabric like felt. Otherwise, I have no problem with sewing 1 layer. I was always able to sew thick layers of felt and leather before the problem happened 2 days ago... I am pretty sure it is a timming problem because I spent long hours looking at the moment when the hook fails to pick up the top thread, but any suggestion is welcome !

Thank you.

Edited November 6, 2013 by cariocastyle

[cariocastyle]

Here is a picture of my 31 K 15, if that helps a little more.

I do not understand how I can move the shuttle driver or the shaft itself, as all the pieces are secured with steel pins. Could it be it that my machine is different on this parts?