The problem is likely to be the rayon thread. I have heard it doesn't stand up to rough use on a finished project as well as other thread also. It sure is pretty and I have perservered on a smaller project with it but it does break. If it works for a while, when it breaks, pull out a few stitches until you have enough to tie the bobbin and upper threads together, put them in aa easy thread hand needle and bury the ends in the quilt sandwich. Carefully put the machine needle in the hole where the sewing stops, bring up your bobbin thread and proceed until the next break, repeat. I have since found a beautiful polyester thread that has the "look" of the rayon but is tougher (Deco Bob by WonderFil) it's polyester.