Brother b837 - Clearance between Rotary Hook and Bobbin Case Opener; Fl] Clearance between Rotary Hook and Needle Plate

IT] CLEARANCE BETWEEN ROTARY HOOK AND NEEDLE PLATE
1.2 mm
~
* Rotary hook 0 is s~t to the proper height by the rotary hook shaft bushing upper so that the clearance between rotary
hook
0 and needle plate f) is set as required (1.2 mm).
m CLEARANCE BETWEEN ROTARY HOOK AND BOBBIN CASE OPENER
* Adjust the clearance between rotary hook 0 and
bobbin case opener f) to about 0.2 mm (when the
bobbin case opener
f) has retracted fully in the arrow
direction) by
loosening screw 8 and moving bobbin
case opener
f) to the right or left.
•
After the adjustment. tighten screw 8 securely.
1. Needle to rotary hook point gap . • . . . . • . • . . . • Rough seams. skipped stitches. thread breakage. needle
breakage
2.
Needle bar rise. height • • • . . . . • • • . • . . • . . . . . . • Rough seams. skipped stitches. thread breakage
3. Rotary hook to
needle plate gap . • • • . . . • . . . . • Too small: improper stitch tightening
4. Rotary hook
to bobbin case opener gap • • . . . •Too large: loose stitches. improper stitch tightening
•Too small: shuttle body damage
• Be sure to readjust rotary hook lubrication when the rotary hook is replaced.
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From the library of: Superior Sewing Machine & Supply LLC