I have just started to get back into free motion quilting - practicing at this point. I am having a problem with my quilt sandwich dragging - it's warm and natural between 2 prices of muslin. And, when I place a supreme slider underneath its even worse. I have adjusted my pressure dial the highest it will go so the only alternative that I can come up with is to adjust the spring on the foot but I have not been able to figure how to do it and I have googled without success. Any help would be most appreciated.