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Singer Slant-o-Matics and free motion quilting?
I found this under a lengthy reply, for 400/500 series, dated 1-20-2020
8. I have come to believe that leaving the lifting needle plate
down with the stitch length set to zero beats putting the needle plate to the
Darning position. Putting the needle plate up changes the relationship with the rotary hook, and I'm not convinced that's a Good Thing.