Thread breakage in stitching question?

[IBQLTN2]

I am asking this question of anyone who has maybe had this happen or of or resident expert Dawn Cav if she can give me a clue. It is the weirdest thing, I quilted a whole quilt with no problems, didn't change a thing and loaded a 2nd quilt all was well until the top thread started snapping in the stitches behind the hopping foot, in other words i would be about 4 or so stitches past the spot that would all of a suddent snap. You could hear and feel it snap, but the machine was past the spot so it isnt like it came unthreaded or anything. the top would look find except a broken stitch, but the bottom side would have an extra thread about an inch or so long caught up in the bobbin stitches. I think it has something to do with the backlash spring, but couldnt really figure out what was wrong. I cleaned and oiled the bobbin case and spring and it still did it. I finally replaced the whole bobbin case with another and that seemed to mostly fix the problem, although it did do it one more time.

My question is what is causing this and how can it be prevented in the future. Do those springs just wear out after a while and should be pitched out or what? thanks for any help, this can be very frustrating when you have to keep stopping with broken stitches.

[DawnCavanaugh]

Jeanne,

Try examining the hook assembly very carefully for any rough spot or burr. A scuff from a broken needle or even a "near miss" can leave just enough of a jagged spot that the top thread snags on it. This causes the top thread to hang up in the bobbin area and linger there while the machine continues to wrap the bobbin thread around the top thread. The top thread can actually look like it broke, but then the machine will pick it up and keep stitching again as if nothing happened.

The bobbin brake spring can eventually wear down to the point where it is no longer applying pressure to the bobbin. When that happens, you'll have over-spin and more bird nests on the quilt back. You can either replace just the bobbin brake spring, or you can replace the entire bobbin case. Replace the case if it has hit the ground a time or two, as it can become "out of round" and then the bobbin will not turn properly inside.

Let me know if you continue to have difficulty even after the new bobbin case, Jeanne!

[IBQLTN2]

Thanks Dawn

I just quilted about a half of a quilt and it seems to have happened at least once again with the new bobbin case. If there is a burr on the hook assembly what do I do to smooth it out:? or do I need a new hook assembly if it keeps happening more. what you describe about it looking like the thread has broken but it just keeps right on going is exactly what it does but the thread actually does snap on the top of the quilt. and every time it happens if I look underneath there is excess thread about an inch long that has become tangled in the bobbin stitches. it is hard to tell if it is top thread or bobbin thread, but I am assuming it is the top thread that had hung up. thanks for your help

[iedquilts]

Jeanne, i have had that happen as well. I thought maybe it was the timing. However, if you use a different color of thread in the bobbin you would be able to tell which is becoming tangled in the stitches.

Awaiting Dawn's reply as well.

Irene

Originally posted by IBQLTN2

Thanks Dawn

..... if I look underneath there is excess thread about an inch long that has become tangled in the bobbin stitches. it is hard to tell if it is top thread or bobbin thread, but I am assuming it is the top thread that had hung up. thanks for your help

[RoseCity Quilter]

I periodically have this problem as well. Very interested in the answer.

[DawnCavanaugh]

Jeanne,

If you find a burr on the hook, rotate the hook until the rough spot is pointing down to the ground. This will keep any small filings from falling into your hook assembly. Use a piece of fine emery cloth (found in the hardware store or in an automotive store) to gently buff the rough spot smooth.

Before you begin, review your manual for an appendix called "Hook Maintenance". This appendix pinpoints the area of the hook that must NOT be changed by filing, as well as areas to check for burrs.

In addition, your manual should include a section about timing the machine. I do not suspect your timing is out of alignment. However, the last step of the timing describes how the hook retaining finger must rest inside the "bobbin basket". Your top thread passes through the opening between the hook retaining finger and the bobbin basket. If that hook retaining finger has a rough spot, or if it is inserted a bit too far, it can also catch the top thread.

To eliminate the bobbin case as the problem, bend up the little "fingers" inside the bobbin case on the backlash spring so that they keep the bobbin resting slightly above the edge of the bobbin case lip. This will ensure that the bobbin backlash spring is doing its job and stopping the bobbin from spinning.

Keep me posted!

[IBQLTN2]

thanks Dawn I am copying and pasting your instructions into my LA info file for safekeeping and referencing. I will take a look at it tonight when I get home and hopefully find the problem. It does not always do it but when it does it can be very frustrating. thanks you are a great help!!