Brother RH-9820, Service Manual

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7. ADJUSTMENTS
RH-9820
147
7-5. Adjusting the looper stroke
The standard looper stroke is 2.7 mm. (It may be preferable to change this depending on the material and thread.)
* Carry out the adjustment in “7-4. Adjusting the needle and looper timing” before making this adjustment.
1. Turn the upper shaft pulley (1) to set the needle bar to the needle drop position at the inside sewing position.
2. At this position, use calipers to measure the length from the edge of the needle bar (2) to the top of the needle bar bush
holder base (3).
3. Add 2.7 mm to the value obtained in step 2 above, and set the width of the calipers to the resulting value.
4. Turn the upper shaft pulley (1) until the edge of the needle bar (2) touches the edge of the calipers, and stop turning the
upper shaft pulley (1) at that point (A).
Push against Should be no gap
5. Tilt back the machine head.
6. Loosen the two set screws (5) of the lower shaft cam (4).
7. With the upper shaft pulley (1) stopped, turn the lower shaft cam (4) to adjust so that the tip of the eye looper (6) is aligned
with the needle center (7).
8. Once adjustment is complete, push the lower shaft cam (4) against the surface of the bearing collar (8), and then securely
tighten the two set screws (5).
0327B 0491B 0490B
0489B
Moves to left
Moves to right