DURKOPP ADLER 911-211, Service Instructions Manual

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Troubleshooting
Service Instructions 911-211 - 02.0 - 10/2016 166
11.4 Errors in sewing process
Error Possible causes Remedial action
Unthreading at seam
beginning Needle thread tension is too
firm Check needle thread tension
Thread breaking Needle thread and hook
thread have not been
threaded correctly Check threading path
Needle is bent or sharp-
edged Replace the needle
Needle is not inserted
correctly into the needle bar Insert the needle correctly into
the needle bar
The thread used is unsuitable Use recommended thread
Thread tensions are too tight
for the thread used Check thread tensions
Thread-guiding parts, such
as thread tube, thread guide
or thread take-up disk, are
sharp-edged Check threading path
Throat plate, hook or spread
have been damaged by the
needle Have parts reworked by
qualified specialists
Missing stitches Needle thread and hook
thread have not been
threaded correctly Check threading path
Needle is blunt or bent Replace the needle
Needle is not inserted
correctly into the needle bar Insert the needle correctly into
the needle bar
The needle thickness used is
unsuitable Use recommended needle
thickness
The reel stand is installed
incorrectly Check the assembly of the reel
stand
Thread tensions are too tight Check thread tensions
Throat plate, hook or spread
have been damaged by the
needle Have parts reworked by
qualified specialists