Adjustment Of Hook-To-Needle Clearance - Pfaff expression 2014 Service Manual

11. Adjustment of hook-to-needle clearance

Requirement:
At the straight stitch setting the distance of the sewing hook point from the bottom of the scarf in the
needle must be 0.05 mm (fig. 33). In the widest zigzag stitch, the sewing hook point must almost touch
the needle.
Check:
Remove the baseplate and the free-arm lid.
Remove the needle.
Remove the presser foot.
Remove the bobbin case.
Remove the bobbin case position finger.
Move the bobbin case base so that the hook point is exposed.
Insert a new needle system 130/705 H size Nm 80.
Select straight stitch program "01".
Turn the handwheel until the hook point is opposite the center line of the needle.
Check the distance between hook point and needle scarf.
Check the axial play of hook 52 to hook shaft bush 54 (fig. 34).
Adjustment:
If the hook shaft has axial play, loosen the two screws 53.
Press bevel gear 56 with the shaft to the front and push sewing hook 52 to the rear.
Tighten the two screws 53.
Loosen screw 57 in the lifting eccentric by 2 - 3 turns.
Loosen screw 55 slightly.
Turn the handwheel and the sewing hook until the hook point is opposite the middle of the needle
scarf.
Shift the sewing hook complete with hook shaft bush 54 until the distance of the sewing hook point to
the bottom of the scarf in the needle is 0.05 mm.
Tighten screw 55 on the narrow flat of the hook bush.
38