Industrial Sewing Machines:

1. Threading issues:

• Make sure the machine is threaded correctly. Refer to the threading diagram in the user manual or on the machine itself.
• Check if the thread is passing through all the thread guides and tension discs. Make sure it is not tangled or twisted.
• Ensure the bobbin is wound correctly and inserted into the machine correctly.
• Make sure the presser foot is raised when threading the machine.

2. Needle issues:

• Ensure that the needle is inserted correctly (that the scarf faces to the right hand side) and is the correct size for the fabric being sewn. Consult the user manual for the correct needle size and type for different fabrics.
• Make sure the needle is not bent or dull. Replace it with a new needle if necessary.
• Check the needle plate for any burrs or damage. A damaged needle plate can cause needle breakage or skipped stitches.

3. Tension issues:

• Check the upper and lower thread tension. Improper tension can cause thread breakage or stitching issues. Adjust the tension according to the user manual or based on the fabric being sewn.
• Ensure the bobbin tension is set correctly. Adjust the tension screw if necessary.

4. Machine issues:

• Check the feed dogs for any damage or obstruction. Make sure they are moving freely and not jammed.
• Check the hook assembly and timing. If the timing is off, it can cause stitching issues. Consult the user manual or a technician to adjust the timing if necessary.
• Ensure the machine is cleaned and oiled regularly to prevent buildup of lint and dust.

If you have tried all of the above and the problem persists, it may be time to contact a qualified sewing machine technician to diagnose and repair the machine.