Mine will distort the fabric if I have the pressure foot pressure to high. Also make sure the darning foot is on correctly. I thought mine was but it wasn't. It was sitting on the shaft at a backward angle. Once I got it installed correctly all was good and I even had to raise the pressure a bit. Get down with a flashlight and make sure everything is lined up and FULLY seated. Also make sure the little arm is resting on the needle screw.