Pfaff 1540 - Manual (Page 40)

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18. Adjustment of the sideways movement of the needle bar
Requirement:
During zigzag sewing operation the sideways movement of the needle should stop above the highest
possible fabric thickness.
The sideways movement of the needle must start when the needle point is leaving the needle plate.
It must be completed before the needle enters the fabric again, approx. 8 mm above the
needle plate (fig. 33).
When hole mark 80 is indicated on the automatic unit bracket (fig. 34) and when during a left-hand
zigzag stitch the point of the rising needle is level with the surface of the needle plate (fig. 35), dot
mark 81 on the large gear wheel 82 must be exactly in the center of the small gear wheel 83 (fig. 36).
Check:
z Unscrew the baseplate.
z Set stitch width adjustment dial to the maximum zigzag width.
z Set needle position adjustment dial to "center".
z Set the adjustment dial of the automatic unit to the "E" position.
z Remove presser foot.
z Turn the handwheel in sewing direction until hole mark 80 is indicated on the automatic unit bracket,
the needle rises on the left-hand side and the needle point is positioned exactly on the surface of the
needle plate.
z Check the position of the dot mark on the large gear wheel in relation to the small gear wheel.
z Slowly rotate the handwheel and check the start of the sideways movement of the needle.
Adjustment:
z Loosen screw 84 on stop 85 for the left-hand needle position.
z Loosen the three fastening screws 86 on worm 87.
z Rotate the handwheel until the point of the rising needle is level with the surface of the needle plate
(fig. 35). The handwheel must not be rotated any further!
z Turn worm 87 to the front until it is flush with the left-hand side and dot mark 80 is indicated in the
position shown in fig. 34.
z Continue to turn worm 87 slowly until the needle begins to move to the right.
z Prevent the stack of cams 88 from rotating by holding it from the front (fig. 37).
z Turn the worm backwards until a little binding can be felt thus making sure that worm 87 and worm
gear 89 have no play (fig. 34).
z Tighten one of the screws 86.
z Check the sideways movement of the needle by rotating the handwheel.
z Check the needle penetration in the needle plate slot.
z If necessary, loosen the two fastening screws 61 on the automatic unit bracket and move the automatic
unit bracket to the left or right, until the needle has the same clearance from the left and right edges of
the needle plate slot.
z Tighten the two fastening screws 61 on the automatic unit bracket.
z Check the setting for sideways needle movement once again and, if necessary, re-adjust.
z Tighten the three fastening screws 86 on worm 87.