Differential Feed - ELNA 745 User Manual

Differential Feed

Differential feed on an overlock is a two-part
feed dog which feeds in the fabric at different
ratios. The front part of the feed dog pushes
more or less fabric under the foot than the
rear part of the feed dog is feeding out. This
feature is useful when sewing knits which
have a tendency to stretch and create waves
when sewn on an overlock machine.
Differential feed is also good on sheer fabrics
which tend to pucker when sewn. Use the 0.5
setting for removing puckers. There are two
kinds of differential feed: negative and
positive.
Standard Feeding
The front and rear feed dogs work as a single
unit. The fabric feeds in and out with the same
ratio.
Positive Feeding
The looser and stretchier the fabric, the more
the front part of the feed dog must feed in and
the less the rear part of the feed dog must
feed out. Waves are eliminated.
Negative Feeding
The front part of the feed dog feeds in less
fabric than the rear part feeds out. The fabric
is held taut by the feed dogs. Puckering is
eliminated.
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