Lockstitch Machine
Troubleshooting
Please click each question item.
Stitch skipping occurs.
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①Is the needle attached correctly?
Check if the needle is inserted all the way, and the direction of the needle is correct.
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②Isn't the presser foot pressure too weak?
Adjust the presser foot pressure according to a sewing object.
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③Are there any scratches on the hook tip?
If there are scratches, fix the hook tip with an oil-stone or replace with a new hook.
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④Is the needle bent?
Replace with a new needle if the needle is bent.
Loose tightening occurs.
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①Isn't the stitch balancing of the needle thread too weak?
Turn the stitch balancing knot clockwise little by little to strengthen the stitch balancing.
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②Isn't the thread take-up spring too weak?
When the spring is too weak, turn the stitch balancing knot clockwise little by little to strengthen.
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③Isn't the thread take-up spring motion too small?
When the motion is too small, turn the needle thread adjuster clockwise little by little to make the working amount large.
Click here for adjustment of thread take-up spring (lock stitch top and ordinary feed)
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④Isn't the bobbin thread balancing too weak?
It is almost not necessary to adjust the bobbin thread balancing; however, a little adjustment may be necessary depending on a sewing material and thread.
The most adequate condition is when a thread edge coming out from the bobbin is lifted, the thread is fed every time you lift the thread edge.
The thread gets cut.
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①Is the needle attached correctly?
Check if the needle is inserted all the way, and the direction of the needle is correct.
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②Isn't the thread take-up spring too strong?
When the spring is too strong, turn the stitch balancing knot counterclockwise little by little to weaken.
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③Isn't the operation of thread take-up spring too fast?
When the operation is too fast, turn the needle thread adjuster counterclockwise little by little to make it slow.
Click here for adjustment of thread take-up spring (lock stitch top and compound feed)
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④Isn't the needle thread balancing too strong?
Turn the stitch balancing knot counterclockwise little by little to weaken the stitch balancing.
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⑤Is the needle bent?
Replace with a new needle if the needle is bent.
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⑥Are there any scratches on the hook and bobbin case?
If there are scratches, fix them with an oil-stone or replace with a new part.
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⑦Are there any scratches on the needle hole of needle plate?
If there are scratches, refine the needle hole or replace with a new needle plate.
The seam gets wrinkled.
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①Isn't the pressure too strong?
Adjust the presser foot pressure according to a sewing material.
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②Isn't the needle thread balancing too strong?
Turn the stitch balancing knot counterclockwise little by little to weaken the stitch balancing.
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③Isn't the bobbin thread balancing too strong?
Turn the stitch balancing screw counterclockwise little by little.
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④Is the feed dog out too much from the needle plate surface?
According to a sewing material, adjust the feed dog height within the range of 0.8 to 1.2 mm.
The seams are not aligned.
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①Isn't the presser foot pressure too weak?
Adjust the presser foot pressure according to a sewing object.
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②Is the feed dog not out enough from the needle plate surface?
According to a sewing material, adjust the feed dog height within the range of 0.8 to 1.2 mm.
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③Is the needle bent?
Replace with a new needle if the needle is bent.
The needle brakes frequently.
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①Is the needle attached correctly?
Check if the needle is inserted all the way, and the direction of the needle is correct.
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②Is the feed timing right?
When the feed and needle encounter is misaligned significantly, the needle is likely to brake. Perform adjustment.
Click here for the relationship between the needle and feed dog (lock stitch total feed).
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③Is the needle bent?
Replace with a new needle if the needle is bent.
