I have a Designer 1 & SE they don't like the thread that start with M.............I have stretched it out, changed needle, and in the beginning used the sewers aid as it was than recommended. However with my Bernina that repair guy said not to use it as it can build up..............I purchase the Sulky, and buy from Superior too, also Robinson -A. Oh I even tryed inverting the spool with M brand..............go figure...............and I almost purchased a thread chest that was offered.........calla