The Pfaff Grand quilter is actually a Tin Lizzie 18 LS. This is the identical machine to the Viking Mega Quilter 18, which is what I have. Look at the screw where the foot is attached. You will see that the foot is actually slotted. Just power the machine off, loosen the screw and push the foot up a tiny bit. Like the thickness of a business card. Do a bit of test stitching and adjust it more if needed.