I recently bought this machine to put on my Gracie II frame. Got it all set up after playing with her to get a good feel for how she sews.....which was wonderful. Now that she is on the frame, my thread keeps breaking as she speeds up. I am thinking it is either the needle or thread causing my problems, so was wondering what size needle I should use on the frame and/or what size and type of thread I should try. When the speed is slow, there are no problems, just when she is sewing fast is when the thread breaks.