Solving Problems - Bernina Industrial 950 Instruction Manual

Solving problems
Trouble Shooting
The reasons for most common problems 1. Irregular seam or irregular thread tension
can be found by checking the following list.
Check if threading of lower and upper thread is correct.
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The thread is caught on or wound round the spool pin.
The needle is too fine for the thread.
The bobbin is damaged and gets stuck in the bobbin case.
The bobbin thread is wound too loosely.
The tension is too loose.
The hook needs lubricating - use thin hook oil (Velocite 10).
Thread remains in the bobbin case or between the upper thread
tension discs.
2. Skipped stitches
Wrong needle system.
The needle is bent, blunt or incorrectly inserted.
The needle is too fine for the thread.
Use the appropriate foot (see pages 8/9 and the BERNINA
Special Accessories
brochure).
3. Thread breaks
Check if threading of upper and lower threads is correct.
Thread is wound round spool pin.
Needle problems (see above)
The tension is too tight for the thread.
Use left-twisted (Z twisted) thread.
The thread quality is poor.
4. Needle breaks
Needle problems (see above).
The needle clamp screw is not properly tightened.
Sew over seams slowly and check that the needle is not deflected by
the thickness.
5. Insufficient feed
Check if the feed-dog (sewing/darning) switch is correctly positioned
to sewing.
Use a special Teflon or Roller foot for fabrics which do not glide
easily.
6. Machine runs slow
Check if the handwheel release is tightened .
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