I have an HQ sweet 16 Sit down. It is set in a table 30in x 36in so it's level with the table. There is 16in between needle and pillar, and I think it't 9in from table to underside of machine. Yes, it only stitches straight stitches and no feed dogs. When I want to stitch in the ditch, I have a small ruler that is a quarter inch thick (can't use regular quilting rulers as the thin ones aren't safe against the foot). I line up the ruler so that my needle will go along the ditch, and move ruler and quilt through, under the needle together. Voila, straight seams!