Sytråden spinner vidare - lila tråd
"Turn the dial to a setting between 1.3 and 2 to make the front feed dog feed a greater amount of fabric. A setting of 2 will move twice as much fabric in front as in back. This setting is helpful to use when sewing knit fabrics to avoid stretching. It also can be used to purposely create gathering on woven fabrics if desired.
Turn the dial to between 0.6 and 0.8 to make the front feed dog motion shorter than that of the back feed dog. This setting helps to eliminate puckering on delicate fabrics. It also can purposely produce a decorative wavy effect, known as lettuce edging, when used on stretchy knits."