I have a Pfaff Grand Quilter Hobby 1200 and I have never had a problem with it breaking the thread. I guess I got a special one because I use any kind of thread on top (cones) and prewound bobbins. It is the greatest but I had to quit quilting with it in the frame. I do my piecing with it and my straight line quilting because it sews so good. I took the frame to the basement because I am disabled and could not use it any more. Just keep trying. Good luck!