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Troubles
Cause (1)
Cause (2)
Checking order and adjusting method
2. Needle breakage
3. Stitch skipping
Threading the needle bar thread guide is wrong.
Bobbin runs idle and the bobbin thread is drawn
out.
Clearance between the needle receiving section
of the shuttle driver and the needle is defective.
Clearance between the needle and the inner hook
is defective.
Feed timing is defective.
Needle strikes the moving knife.
Needle strikes the intermediate presser.
Needle strikes the wiper.
Needle is bent.
Needle is too thin.
Clearance between the needle and the inner hook
is excessive.
Maladjustment of the needle to the inner hook
timing
Clearance between the needle receiving section
of the shuttle driver and the needle is defective.
Material to be sewn is not properly stretched.
Needle is bent or blunt.
Defective initial position of the moving knife
Feed timing against cloth pressure is retarded.
Needle thread tension is too high.
Clearance between the intermediate presser and
the material to be sewn is large.
Perform threading again.
Strengthen the idle prevention spring.
Properly adjust the initial position of the moving knife.
Properly adjust the clearance between the needle and the shuttle
driver.
Properly adjust the clearance between the needle and the inner
hook.
Change the feed timing using the memory switch.
Properly adjust the position of the moving knife.
Properly adjust the holding position of the intermediate presser
bar.
Properly adjust the installing position of the wiper.
Properly adjust the tension.
Change the needle No. to the suitable one to the material.
Properly adjust the clearance between the needle and the inner
hook.
Properly adjust the needle to the inner hook timing.
Properly adjust the clearance between the needle and the shuttle
driver.
Properly adjust the height of the intermediate presser.
Remove the slack of the material to be sewn.
Replace the needle.
