Position Detector Adjustment; Corner Sewing Position Adjustment - Brother b831 Service Manual

M POSITION DETECTOR ADJUSTMENT
Red dot
Needle down stop position Needle up stop position /
Approx. 16 mm
42-39
1. Thread cutter element
Set the thread cutter element O to 0.5 on the position detector scale.
2. Needle down stop position
Set the needle down stop element O to 2.5 on the position detector scale.
3. Needle up stop position
Adjust the needle up stop element O so the red dot on the arm and the pulley index are aligned when the treadle is
pressed to reverse. (The needle up stop element should be at approximately 8 on the position detector scale.)
[Adjustment]
Loosen screw O- and move the thread cutter element O- needle down stop element O- and needle up stop element O.
respectively.
QZI CORNER SEWING POSITION ADJUSTMENT (B835 B836)
1. Needle feed rocker crank adjustment
Turn the center screw O in the fork of the slide arm O
so the needle feed rocker crank O fits in the fork.
Tighten nut O after the adjustment iscompleted to hold
the crank secure in the fork.
Stiff needle feed rocker crank O operation will make the needle bar stiff, too.
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