I love Bernina machines, but you don't have good presser foot tension. That's how tight the fabric is squeezed between the feed dogs and presser foot. A few Bernina 350's are lacking in that area, and you can't adjust it. As a Bernina tech, I can't adjust it, either. It's sad.... You could ask your Bernina tech if they can call and talk to Hans and see if there's a solution.