So Frustrated!
Last year I bought a Juki TL2010Q from a local dealer. It is doing a very weird thing - I will describe as best I can.
I'll be sewing right along and the upper thread gets momentarily "caught" on something under the throat plate. I can feel a little hitch when it happens, I can hear it ping when it releases, like it's caught on something metal. I am able to continue to sew. When I examine the bobbin side of the pieced block, there are lengths of top thread caught in the bottom stitches. The stitching also puckers slightly at that point, like the tension goes off for just a couple of stitches. I can actually pull the pieces of top thread free from underneath the bottom stitches; usually the piece of thread is about two-three inches long. I have no idea how this can even happen, because the top thread is not broken (the seam is intact). I can't wrap my head around this! Obviously the top thread is breaking and getting caught up under the bobbin thread, but there is no evidence that the top thread has broken when you look at the stitching of the seam.
I have taken the machine into the dealer three times for this problem in the last year, the first time about a month after I bought it. The repair person was unable to find anything wrong with it. He said perhaps I was sewing too fast (I don't, but even if I did...) or I had the tension set wrong. I know it's not, because I put different colored threads in the top and bottom to check the tension (which is how I know it's the top thread getting caught underneath) and when testing the tension it looks fine to me.
Thanks for reading. If anyone has experienced this type of problem, please let me know.
Loving a cool summer day in California!