YOU MIGHT HAVE TO CHANGE THE TENSION, IF YOU ARE WORKING WITH LAYERS YOUR TENSION MAY HAVE TO BE CHANGED. THIS ALSO APPLIES TO THE THREAD, YOU MAY HAVE TO CHANGE THE THREAD OR THE NEEDLE TO SUIT THE TYPE OF THREAD YOU ARE USING. SPEED ALSO HAS TO DO ALOT WITH THE THREAD BREAKING. YOU HAVE TO GET THE RIGHT SPEED ON OUR QUILTING. GOING TO FAST CAN BREAK THE THREAD OR GOING TO SLOW. JUST ORK WITH THE SPEED AND KEEP IT STEADY. I FIND THAT THIS HELPS ME.