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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)Feed timing is slow in regard
Change the feed timing by the use of the memory switch.
to the work pressure.
2-4)Needle coming in contact Adjust the moving knife position.
with the moving knife
Adjust the work clamp foot (feed bracket) position.
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.
6-B)The presser bar treads on the Increase the crosswise clearance between the wiper
needle thread at the beginning and the needle. 23 ~ 25mm
of sewing and the wiper is caught.
2-7) Needle is too thin.
Change the needle No. to the suitable one to the material.
From the previous page
Trouble Cause (1) Cause (2) Check and corrective measures
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