Adjusting The Upper Thread Scissors Gradual Opening Timing - Brother HE-800B Service Manual

7. ADJUSTMENT

7-12-7. Adjusting the upper thread scissors gradual opening timing

4104M
Start touching at 1.5 - 2.5 mm
4106M
1. Turn on the power and set the sewing machine to the home position. Then press the THREAD key to lower the work clamp.
2. Loosen the two bolts (3), and then adjust so that the distance b between ridge line B on the opening cam (1) and the upper
thread scissors (2) is 0.5 mm, and so that ridge line B on the opening cam is parallel to the feed direction.
3. Loosen the two screws (4), and then adjust so that the distance c between the rising section C of the upper thread scissors
(2) and the tip of the opening cam (1) is approximately 0.5 mm when the upper thread scissors (2) are closed.
* If you would like the scissors to start opening earlier, make the distance smaller. However, if you make the distance
smaller, check that the rising section C of the upper thread scissors (2) does not touch the opening cam (1) and prevent
the upper thread scissors (2) from opening when the work clamp is lowered.
4. Apply grease to the inclined face D of the opening cam (1).
5. Check that the upper thread scissors (2) gradually start opening after the material has been fed by 1.5 - 2.5 mm.
101
Approx. 0.5 mm
Approx. 0.5 mm
HE-800B
4105M