I don't have a Bernina, however, after free motion quilting for a couple years on my domestic, then progressing to a long arm, I would be really afraid to try using a ruler on a domestic machine. I'm not really sure how you could keep the ruler AND fabric sandwich firmly against the foot. Even with a long arm, you have to be very careful not to get the ruler caught under the foot. You can not only damage the foot, you can throw the timing off.