If you are quilting, not piecing, as your post sounds like, here are two more ideas. I had a quilting instructor once tell me to always use a "TOPSTITCH" ( I prefer a size14) needle when quilting. I can guarantee if there is nothing mechanically wrong with your machine that will make a difference. Also be sure your whole quilt is supported even with your machine. If your quilt is hanging over the edge of your sewing area the drag from pulling the quilt will effect your stitches. Good luck and welcome to the board. Great bunch of people and always helpful.