4. ADJUSTMENT
HE-800A
94
4-14-7. Adjusting the upper thread scissors gradual opening timing
1. Turn on the power and set the sewing machine to the home position. Then press the RESET key to lower the
work clamp.
2. Loosen the two bolts (3), and then adjust so that the distance a between ridge line A on the opening cam (1)
and the upper thread scissors (2) is 0.5 mm, and so that ridge line A on the opening cam is parallel to the feed
direction.
3. Loosen the two screws (4), and then adjust so that the distance b between the rising section B 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 B 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 C 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.
4336Q
4335Q
4334Q
Approx. 0.5mm
Approx. 0.5mm
Start touching at 1.5 - 2.5mm
