Sewing Hook Timing - Pfaff expression 2014 Service Manual

12. Hook timing
Requirement:
When the needle bar has moved 2.2 mm upwards from its lowest position (with the machine set for
straight stitch and center needle position), the sewing hook point must be exactly opposite the center line
of the needle (fig. 36).
Check:
Remove the presser foot and the needle plate.
Select stitch pattern "01" for straight stitch.
Bring the needle bar to its lowest position by turning the handwheel (fig. 35).
Set the spacer (63-102 600-18) on top of the needle bar and push it upwards against the needle bar
frame.
Push the needle-rise clamp (61-111 600-35) on the needle bar and tighten it lightly.
Push the 2.2 mm feeler gauge (00-870 136-01) with its cutout on the needle bar above the needle-rise
clamp.
Loosen the needle-rise clamp and push the 2.2 mm feeler gauge upwards against the spacer.
Tighten the milled screw on the needle-rise clamp.
Turn the handwheel back and forth a little.
If there is any play on the feeler gauge, repeat this procedure.
Remove the 2.2 mm feeler gauge.
Turn the handwheel in sewing direction until the needle-rise clamp is in contact with the spacer
(fig. 36).
By this means the needle has moved upwards to the needle rise position of 2.2 mm.
The hook point must now be exactly behind the center line of the needle.
Adjustment:
If the setting is not correct, remove the needle-rise clamp.
Loosen the two screws 53 (fig. 37).
Re-fit the needle-rise clamp and repeat the operation as described under "Check", until the needle bar
has moved 2.2 mm upwards and the needle-rise clamp is in contact with the spacer.
Turn the hook until the hook point is exactly behind the center line of the needle.
Press sewing hook 52 and bevel gear 56 together so that there is no play between them, and tighten
one of screws 53.
Cross-check:
Turn the handwheel a little backwards and then forwards until the needle-rise clamp rests on the
spacer (fig. 36).
The hook point must be exactly behind the center line of the needle.
Remove the needle-rise clamp.
Check that the hook shaft has no axial play.
Tighten the two screws 53 very firmly.
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