I have a Designer 1 sewing machine. My problem when I try and free motion the thread keeps shredding. I have tried changing the thread-changing the bobbins from prewond to regular hus. bobbins-changing the throat plate from zigzag to 1 hole-changed the size needle exp. quilting, embroidery,universal-putting a magic bobbin washer in and without-changed color thread on spool holder and in bobbin-different feet exp q foot-darning foot etc -setting my machine on q foot or free motion-feed dogs up or down. I can change to regular sewing and it works fine.