Singer 3337 Instruction Manual page 29

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TROUBLESHOOTING AND MAINTENANCE
Troubleshooting
7. BOBBIN WINDING DIFFICULTIES
Possible Cause: Bobbin thread loosely wound on bobbin.
Solution: Rewind bobbin, making sure that the thread is placed snuggly in the bobbin winding
tension disk. (See Page 12)
Possible Cause: Bobbin winding spindle not fully engaged, therefore bobbin not winding.
Solution: Check that the bobbin winding spindle has been fully engaged before starting to wind.
(See Page 12)
Possible Cause: Bobbin is winding sloppily because thread end not held at beginning of winding
process.
Solution: Before starting to wind, hold the thread tail (coming out of the bobbin) securely, allow the
bobbin to partially fill, then stop to trim the thread tail close to the bobbin. (See Page 12)
8. BOBBIN THREAD BREAKING
Possible Cause: Bobbin threaded incorrectly.
Solution: Check that bobbin is placed correctly in the bobbin case. (See Page 13)
Possible Cause: Bobbin wound too full or unevenly.
Solution: Bobbin thread may not have been correctly placed into bobbin winding tension disk
during the bobbin winding process. (See Page 12)
Possible Cause: Dirt or lint in bobbin case.
Solution: Clean bobbin case. (See Page 32)
Possible Cause: Wrong bobbins being used.
Solution: Use SINGER bobbins that are the same style as those that come with the machine –
®
don't substitute. Your machine comes with SINGER Class 15 transparent bobbins.
®
9. NEEDLES BREAKING
Possible Cause: Bent, dull or damaged needle.
Solution: Discard needle, insert new needle. (See Page 25)
Possible Cause: Wrong size needle for fabric.
Solution: Insert appropriate needle for fabric type. (Go to www.singerco.com to view the Stitch
Reference Guide)
Possible Cause: Machine not threaded correctly.
Solution: Rethread the machine completely. (See Page 14)
Possible Cause: "Pushing" or "pulling" fabric.
Solution: Don't manually push/pull fabric in order to sew, but allow the machine's feed teeth to
draw fabric under the presser foot as you guide it. (See Page 20)
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