Brother HE-800B - Uneven Seams (4); Uneven Seams (6); Uneven Seams (7)

HE-800B
11. TROUBLESHOOTING
153
11-6. Uneven seams (4) …… Uneven sewing pitch at the sewing start
Bird’s nests form at the sewing start, and after 5 - 6 mm the sewing pitch suddenly increases
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause
Check
Remedy
Page
Lower thread clamp
Lower thread clamp
opening timing
Advance the timing at which the lower thread clamp
starts to open.
105
11-7. Uneven seams (5)……Poor rounding of seam
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause
Check
Remedy
Page
Thread tension
Zigzag thread upper thread
tension
Adjust the upper thread tension appropriately.
INSTRUCTION
MANUAL CD
Zigzag tension disc
opening
・Check the opening of the zigzag tension discs.
・
Replace the tension release solenoid.
108
Lower thread tension
Adjust the lower thread tension appropriately.
INSTRUCTION
MANUAL CD
Threading Upper thread threading Thread the upper thread correctly.
INSTRUCTION
MANUAL CD
Lower thread threading
Thread the lower thread correctly.
INSTRUCTION
MANUAL CD
Stitch patterns
Purl stitch, whip stitch
Set using parameter number 53.
INSTRUCTION
MANUAL CD
Tension release Tension release timing
Use parameter numbers 54 to 57 to set the timing for
changing the thread tension.
INSTRUCTION
MANUAL CD
11-8. Uneven seams (6) …… Around rear tack or front tack
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause
Check
Remedy
Page
Tension release
Tension release timing
Use parameter numbers 54 to 57 to set the timing for
changing the thread tension.
INSTRUCTION
MANUAL CD
Threading
Upper thread threading
Thread the upper thread correctly.
INSTRUCTION
MANUAL CD
Lower thread threading Thread the lower thread correctly.
INSTRUCTION
MANUAL CD
Zigzag thread tension
Zigzag tension disc
opening
・Adjust the tension disc opening amount.
・Check the opening of the zigzag tension discs.
・Replace the tension release solenoid.
108
Upper thread trimmer
Upper thread trimmer
operation
Apply grease to the inclined face of the opening cam.
101
11-9. Uneven seams (7) …… Loose thread end at end backtack
Cause
Check
Remedy
Page
Backtack shape
Checking the number of
end backtack stitches
Checking the end backtack
width
Adjust the setting values for parameter numbers 51
and 52.
INSTRUCTION
MANUAL CD