DURKOPP ADLER 559 Operating, Installation And Servicing Instructions page 68

Description of fault
Thread breakage
Loose stitches
The buttonhole is cut open
inaccurately
66
Possible cause
Thread-guiding parts as e.g.
thread pipes, thread guides or
the rotary thread take-up disc
have sharp edges.
Check whether the throat plate,
the hooks or the spreaders
have been damaged by the
needle.
The thread tensions are not
adapted to the material, the
material thickness or the
threads used.
Needle and hook thread are
threaded incorrectly.
The set cutting pressure is too
low.
Too short duty cycle of the
cutting stamp
The knife edge is blunt or
chipped.
The knife works on a
non-matching cutting block.
No matter whether buttonholes
are cut open before or after
sewing or buttonholes with or
without eyelet are sewn, always
insert the matching cutting
block.
Cutting blocks with two knife
marks lead to an inaccurate
cut.
Error elimination
Check whether thread-guiding parts
are sharp-edged.
Have the parts reworked by the
service personnel.
Check the thread tensions
(see Operating Instructions "Thread
tensions").
Check the threading of needle and
hook thread (see Operating
Instructions "Thread the needle
thread", "Thread the hook thread").
Increase the cutting pressure (see
chapter "Cutting pressure")
Increase the duty cycle
(See menu item 504)
Insert a new knife
(see chapter "Cutting knife / Eyelet
knife").
Rework the cutting block or insert a
new one.
(see chapter "Adapting the cutting
blocks").