Help!!! Straight line quilting stitches breaking
 

I hope someone can help me. I am straight line quilting a large (120x120) quilt on the diagonal both directions for a square that looks like a diamond. I had sewn about 1/3 of the first direction, when I went to turn the quilt for next line I gave the quilt a little tug and my finished stitches started to break. I checked the other lines of stitching and they all break with a tug. This quilt is to be used and it will be tugged on so now I am removing all the stitches and will start over. But I don't know how to correct the problem. I am using King Tut #40/3 ELS Cotton. I did the break test and it is very strong. I am using a Juki TL-2010Q with a walking foot. Do you think this could be a tension problem? If so which tension do I adjust? [h=3][/h]

I will be watching this link...are yiu using the same stitch length you usually use? Are you stitches flat to the surface of your quilt? Sorry that is the only things that come to mind with information your provided hole someone else will know the answer.

Judy in Phx, AZ

Before re-quilting on your quilt I would make up a test quilt sandwich and sew a few lines and see what happens. If it is the thread, get rid of it - or save it for basting only. I can't image it being the tension without seeing it in the quilting with lots of puckering. You can try different thread and see if it keeps happening.
Are you using the same thread in the bobbin as you use on the top? Some people say that polyester thread will cut cotton thread. I have not had this problem. I did have some very old thread do it - but it was over 70 years old and that doesn't seem to be the situation here.

I am making a test quilt piece. I am using same thread in the bobbin. The thread seems very strong when I wrap it around my fingers and break it take considerable force. I don't plan on taking any chances I am changing to stronger polyester thread. There are no puckers the seams lay flat and looked good. So much for looks. LOL

What is the stitch length? My suspicion is that the stitches are too small. I usually sew mine at 3 or even 3.5 mm.

Are you using a walking foot and are you going nice and slow?

Do you have all of the quilt well supported on the table or does any of it hang over and cause drag over the edges of the machine?

All of those issues can contribute to problematic stitches. Good luck.

If you could tolerate the look - set your stitch at a very narrow zigzag and use the regular stitch length (2.5 or so - depending on what you like) - the narrow zigzag would allow for some "stretch" on the diagonal.

Basocally - what Tartan just said.

Thank you for all your help. I spent most of this afternoon resetting the tension and stitch length on my machine and checking stitches on a test quilt. I can now sew on the diagonal and not break stitches unless I really stretch the fabric. Just to be safe I am going to use a stronger thread that didn't break even when I really stretched the test quilt.

Did you cut the thread before turning the quilt to start a new line of stitching? My stitches will break if I tug with the thread still in the needle.

This was my first thought too. Stitches need to be longer for quilting as they also have to go through the depth of the fabric and batting.