I was having thread breakage too but found out I needed to bump up the size needle I was using. Back in 2000 when embroidery machines became the rage we were taught to use a 75/11 needle. Seems since then the normal size needle is larger. I had to go up to a 90/14 to finally get the thread to play nicely. Got thru a 45 minute design without a break. So I've decided to use my huge lot of 75/11 needles for piecing from now on.