Differential Feed - White SUPERLOCK 634D Instruction Book

7. DIFFERENTIAL FEED
Differential feed prevents stretching or puckering
fabrics, since two independent feed dogs, one in
front and one behind the needles, can be adjusted
to feed at different ratio.
This function produces a neat finish of overlock for
stretchable and lightweight fabrics.
+ "N" indicates the normal position.
Refer to the chart below and test stitch performance
on a scrap of material you are going to use.
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