Adjusting The Needle And Looper Timing - Brother DH4-B981 Instruction Manual

9-2. Adjusting the needle and looper timing

The distance by which the needle bar rises from its lowest position to the position where the tip of the eye looper and
the center of the needle are aligned should be the same as the distance from its lowest position to the position where
the tip of the right looper and the center of the needle are aligned.
Before adjusting the looper timing, first adjust the stitch width (needle racking width).
* Refer to "Adjusting the needle racking width (stitch width)" on page 57. The standard width is 3 mm.
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1. Move the needle bar to its lowest position.
2. Use calipers to measure the distance between the end of the needle bar q and the top of the holder base w when
the needle bar is at its lowest position.
3. Turn the upper shaft pulley until the tip of the eye looper r and the center of the needle e are aligned when the
needle e is at the inside sewing position, and then use the calipers to take the same measurement as taken in
3.
3. step 2. Find the difference between the measurements taken in this step and in step 2.
4. Follow the same procedure as in step 3. above to find the difference between the two measurements when the
needle e is at the outside sewing position.
4.
* When the needle e is at the inside sewing position, the tip of the eye looper r should be aligned with the center
4.
of the needle e, and when the needle e is at the outside sewing position, the tip of the right looper t should be
4. *
aligned with the center of the needle e.
4. *
* The distance from the end of the needle bar q and the top of the holder base w should be the same when the
4.
needle e is at both the inside sewing position and the outside sewing position.
i
u
y
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5. If adjustment is necessary, turn the looper base y in the direction indicated by the arrow in the illustration, loosen
the screw u, and then move the looper link clamp i up or down to tilt the LS-holder bracket o to the left or right
5.
5. (in the direction of the arrow).
Lowest position
of needle bar
q
w
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DH4-B981
9. STANDARD ADJUSTMENTS
When center of needle and
looper tip are aligned
e
r
o
e
t
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