Brother International HE-800B Instruction Manual - English - Page 89

Uneven seams (1) …… At the sewing start, Bobbin holder spring

Page 89 highlights

11. TROUBLESHOOTING 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 Upper thread trimmer Installation height Adjust the upper thread trimmer installation height. Upper thread trimmer Adjust to an appropriate opening timing. opening timing Upper thread trimmer Apply grease to the inclined face of the opening cam. operation 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. Page 68* 69* 69* Screw Decrease Increase * Lower thread (bobbin Lower thread tension slip) Bobbin holder spring 4000Q Adjust the lower thread tension appropriately. 26 Add tension to the bobbin holder spring. . Add tension to the spring by the same amount that the bobbin tab is projecting. * Make a gap Lower thread position 4001Q retainer Adjust the lower thread retainer position. * Adjust lower thread retainer so that a 35 - 40 mm thread leader is left after trimming. * 35 - 40mm Bobbin presser position Bobbin insertion Adjust the bobbin presser position. Insert the bobbin correctly. 4002Q 70* 25 HE-800B 80

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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