Lower Thread Tension - Brother XM3700 Service Manual

Adjustment
[Standard]
When the schappe spun thread #60 is pulled from the inner rotary hook assy slowly with
the tension gauge, the thread tension should be 0.1 to 0.12 N (10 to 12 gf).
[Adjustment]
1. Remove the 2 screws 1 of the needle plate assy, and remove the needle plate assy.
1
2. Remove the inner rotary hook assy from the machine.
3. Set the bobbin (the schappe spun thread #60) in the inner rotary hook assy, and pass the thread through the
groove of the thread tension plate.
*Key point
• Pass the thread through into the back of the groove of the thread tension plate.
Schappe spun thread #60
Bobbin
Inner rotary hook assy
4. Pull the thread slowly from the inner rotary hook assy with the tension gauge, and measure the thread tension.
5. Adjust the thread tension by turning the tension adjusting screw of the inner rotary hook assy.
*Key point
• The tension adjusting screw is secured with the thread locker.
6. Secure the tension adjusting screw to the inner rotary hook assy by applying a small amount of the thread
locker to the tension adjusting screw.
Schappe spun thread #60
Tension adjusting screw

Lower thread tension

Screw
needle plate
Thread tension plate
0.1 - 0.12 N (10 - 12 gf)
4 - 44
Inner rotary hook assy
Flat screwdriver
Schappe spun
thread #60