Adjusting The Position Of The Thread Trimmer Lever Bracket; 4-22.Adjusting The Lower Thread Trimmer (-01 Specification); 4-22-1.Adjusting The Knife Pressure - Brother RH-981A Service Manual

4. ADJUSTMENT

4-21-2. Adjusting the position of the thread trimmer lever bracket

When the needle is swinging to the right with the maximum stitch width, the needle should be able to pass the upper
movable knife sufficiently.
4-22. Adjusting the lower thread trimmer (-01 specification)
[Adjusting the thread trimmer which can cut the lower thread and gimp, leaving them longer]
The thread trimmer is operated by means of an air cylinder when the feed bracket is returned to the home position.
4-22-1. Adjusting the knife pressure
Adjust the knife pressure so that the thread can be cut neatly.
Note: Do not subject the knife to excessive pressure. It may cause the knife to wear quickly or damage it.
Match mark
3803Q
Loosen the two screws (1), and move the fixed knife setting bracket (2) along the slot which the screws (1) are in, in
the direction of the arrow.
* The standard adjustment is done as shown in the above enlarged view, which indicates the first point to make contact
with the point of the fixed knife (4) and the pin of the movable knife (5) when the thread trimmer arm (3) operates.
63
3802Q
Align the pin with the point
of the fixed knife (4).
RH-981A
Loosen the nut (1), and turn the screw (2) to adjust the
position of the thread trimmer lever bracket.
At this time, dimension a to the shoulder of the thread
trimmer lever bracket should be 10 mm.
Note: Turn the looper base, and make sure that the
thread trimmer lever bracket can smoothly go in
under the thread trimmer lever hammer. The
height of the thread trimmer lever hammer is
adjusted to 11 mm.
Decrease
pressure.
Increase
pressure.
3804Q