I learned to sew in Junior High, but when I was in HS and my mother purchased her own sewing machine (I took over the Singer Treadle) she kept having this problem. She fixed it by using a playing card (thin and coated so glides easily) and would clean out the tension discs. We figured out the problem was because she had been changing threads by pulling the thread up from the needle and machine using the spool of thread when changing spools, instead of cutting off the thread and pulling the threads downward toward the needle. I can honestly say I have never pulled the thread out by the spool, as what a pain it was to remember to clean those discs for her. Thread goes downward from the spool toward the needle when sewing. That is the same way I take it out when changing thread. And I change a LOT when using my embroidery machine. I can't get to any tension area on my Babylock Ellegante, so would have to take it in. I still use a playing card on my Babylock Jane, and follow up with dental floss. Glad you came up with a solution instead of having to take it in.