Uneven Seams; Lower Thread Is Lifted Up At; The Sewing Start - Brother HE-800A User Manual

16. TROUBLESHOOTING
Cause
Lower thread (bobbin Lower thread tension
slip)
Bobbin holder spring
Lower
position
Bobbin presser position
Bobbin insertion
Work clamp lifting speed
- . Uneven seams (2) ...... Lower thread is lifted up at the sewing start
The end of the lower thread protrudes above the seam at the sewing start
Cause
Lower thread Lower
retainer amount
Lower thread clamp Lower
opening timing
Lower thread clamping
force
95
Check
Adjust the lower thread tension appropriately.
Add tension to the bobbin holder spring.
.
thread retainer Adjust the lower thread retainer position.
* Adjust lower thread retainer so that a 35 – 40 mm
thread leader is left after trimming.
Adjust the bobbin presser position.
Insert the bobbin correctly.
Reduce the setting for memory switch No. 02.
Check
thread retaining Adjust the lower thread retaining amount.
thread clamp Adjust so that the lower thread clamp plate opens
when the feed mechanism moves 6 – 7 mm.
If the lower thread clamp and lower thread presser
are bent, replace them.
Check that the screws are tightened.
Lower thread
clamp
HE-800A
Remedy
Add tension to the spring by the same
amount that the bobbin tab is projecting
Make a gap
35 - 40mm
Remedy
Page
61
-
4001Q
-
4002Q
77
60
79
Page
-
4003Q
77
Screw
-
3999Q