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1-4) Material to be sewn is not
Remove the slack of the material to be sewn.
properly stretched.
1-5) Unstable needle thread clamp
5-A) Thread tends to be extended
Increase the needle thread clamp needle number to
or sliding efficiency is worse.
3~4 stitches.
Lower the speed of the first stitch. (600 ~ 1000rpm)
5-B) Pitch of the first stitch is too small.
Lower the needle thread tension of the first stitch.
Increase the pitch of the first stitch.
1-6) Threading the needle bar
Refer to the item “Threading the needle bar thread
thread guide is wrong.
Guide”.
1-7) Bobbin runs idle and the bobbin
Use a stronger idling prevention spring.
thread is drawn out.
7-A) Initial positioning of the mov-
Adjust the initial position of the moving knife.
ing knife is inadequate.
2. Needle breakage
2-1) Inadequate clearance between
Adjust the clearance between needle and shuttle driver.
the shuttle driver and the
needle
2-2) Inadequate clearance between
Adjust the clearance between the needle and the
the needle and the inner hook.
inner hook.
2-3) Feed timing is defective
3-A) Too late feed timing for cloth
Change the feed timing by the use of the memory switch.
thickness
2-4) Needle coming in contact
Adjust the moving knife position.
with the moving knife
2-5) Needle coming in contact
Adjust the wiper position.
with the wiper
2-6) Needle is bent
6-A) The needle thread tension is
Adjust the tension to a proper level.
too high.
2-7) Needle is too thin.
Change the needle No. to the suitable one to the material.
2-8) Interference between work
Adjust the work clamp foot (feed bracket) position.
clamp foot and needle
From the previous page
Trouble
Cause (1)
Cause (2)
Check and corrective measures