HE-800B
11. TROUBLESHOOTING
80
11-3. Uneven seams (1) …… At the sewing start
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause Check
Remedy
Page
Installation height
Adjust the upper thread trimmer installation height.
68*
Upper thread trimmer
opening timing
Adjust to an appropriate opening timing.
69*
Upper thread trimmer
Upper thread trimmer
operation
Apply grease to the inclined face of the opening cam.
69*
Upper thread feeding
Thread take-up amount
Loosen the screw to decrease thread take-up amount
so that upper thread does not pull out of trimmer
assembly at the sewing start.
*
Lower thread tension
Adjust the lower thread tension appropriately.
26
Bobbin holder spring
Add tension to the bobbin holder spring.
.
*
Lower thread retainer
position
Adjust the lower thread retainer position.
* Adjust lower thread retainer so that a 35 - 40 mm
thread leader is left after trimming.
*
Bobbin presser position
Adjust the bobbin presser position.
70*
Lower thread (bobbin
slip)
Bobbin insertion
Insert the bobbin correctly.
25
4000Q
Screw
Increase
Decrease
4001Q
Add tension to the spring by the same
amount that the bobbin tab is projecting.
Make a gap
4002Q
35 - 40mm