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Troubles
Cause (1)
Cause (2)
Checking order and adjusting method
(2) With regard to sewing
1. Thread comes off at the start of sewing
Stitch skipping at the 1st stitch
Length of thread remaining at the needle is not
sufficient.
Length of bobbin thread remaining is not sufficient.
Material to be sewn is not properly stretched.
Penetration registance of the thread against the
cloth is small.
Tension controller No. 1 provides an excessive
tension.
Tension release timing is excessively retarded.
Rising amount of tension disk No. 2 is small.
Stroke of the thread take-up spring is large.
Tension of the thread take-up spring is low.
Level difference between the needle hole guide
and the counter knife is excessively high.
Needle thread tension is high and the thread is
excessively stretched.
Thread spreading section of the moving knife has
scratches.
Level difference between the needle hole guide
and the counter knife is excessively high.
Lower face of the needle hole guide has scratches.
Thread spreading section of the moving knife has
scratches.
Shuttle upper spring has scratches.
Bobbin thread tension is too high.
Bobbin or bobbin case has scratches.
Clearance between the intermediate presser and
the material to be sewn is large.
Decrease the sewing speed at the start of sewing.
Lower the needle count to be used.
Properly adjust the tension controller No. 1.
Properly adjust the position of the tension release notch.
Properly adjust the rising amount of the tension disk No. 2.
Properly adjust the stroke of the thread take-up spring.
Properly adjust the tension of the thread take-up spring.
Properly adjust the heigt of the counter knife.
Properly adjust the needle thread tension.
Polish the thread spreading section of the moving knife with buff
or replace the knife.
Properly adjust the height of the counter knife.
Polish the needle hole guide with buff or replace it.
Polish the thread spreading section of the moving knife with buff
or replace the knife.
Polish the shuttle upper spring with buff or replace it.
Properly adjust the bobbin thread tension.
Polish with buff or replace it.
Remove the slack of the material to be sewn.
Properly adjust the height of the intermediate presser.