Duerkopp Adler 171 Service Manual page 18

Condensed stitch length of the top puller feed
The puller should always feed slightly more than
the bottom feed.
The material is thus tensioned, thereby preventing
seam pucker.
When the condensed stitch length of the bottom
feed is eg 1.2 mm, the feed of the puller is to be
adjusted to 1.3 mm.
Reduce the sewing foot pressure such that thin
cardboard can just pass between the sewing foot
and feed dog.
Lower the puller.
Make condensed stitches on thin cardboard by
pressing the button at the sewing head.
11 stitches must be equal to 13 mm.
Adjust the stopper 8 accordingly.
The lock nut 7 and the stopper 8 are also ac-
cessible with screwed on top cover plate.
8 7
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