Adjusting The Lower Thread Clamp Opening Amount; Adjusting The Bobbin Presser - Brother HE-800B Service Manual

7-13-4. Adjusting the lower thread clamp opening amount

Approx.
5 mm

7-14. Adjusting the bobbin presser

3989Q
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 set screw (1), and then adjust so that the bobbin presser (2) goes into the hole in the bobbin case (3).
3. Check that the work clamp is at the home position, and then loosen the nut (4) and turn the screw (5) to adjust the clearance
A between the bobbin presser (2) and the edge of the bed to approximately 12.5 mm.
4. Turn off the power, move the lower thread trimmer cam lever (6) by hand in the direction of the arrow to check that the
bobbin presser (2) presses the bobbin firmly before the lower thread retainer (7) starts to hold the lower thread.
Note: If this timing is reversed, it will cause problems such as an excess trailing length of upper thread.
Loosen the two screws (6), and then adjust so that the
distance between the lower thread clamp (4) and the
lower thread presser (5) is approximately 5 mm when the
feed guide shaft (1) is projecting out at the front and is
firmly touching the roller (3) of opening plate (2).
4350Q
HE-800B
7. ADJUSTMENT
4351Q
4352Q
106