Play
Once the alignment is complete, make sure that the plunger (rib shaft) has no axial
play. Any play can be corrected by a tighter setting of the set collar or the pivot
screws on the plunger shaft.
If the plunger (rib shaft) has any radial play, this can be remedied by readjustment.
On classes 221, 271 and on the right-hand plunger (rib shaft) on classes 252, 352,
this is carried out by adjusting the pivot screws. (Classes 221, 271, see spare parts
list, page 10, item 35, classes 252, 352, see spare parts list, page 4, item 73).
On classes 240, 241, 250, 251, 261, this is carried out by adjusting the two set collars
on the plunger shaft.
Make sure that the machine does not become stiff.
Please remember to the lock the cone screw again with the appropriate nut.
Setting the plunger (rib shaft) timing
To ensure accurate penetration, the plunger (rib shaft) must stop when the needle
passes over it. The return movement must only start when the needle eye crosses
the plunger tip on the forward movement of the needle. This can be checked by
turning the hand-wheel slowly.
If the plunger (rib shaft) moves earlier or later, the following adjustment is necessary:
Slacken screws D at the back of the machine (Fig. 22), then turn the hand-wheel until
the needle point is positioned in the middle of the stitch plate cut-out. Now turn the
eccentric E forwards or backwards until the plunger (rib shaft) is at its rear reversing
position. During the adjustment, hold the needle stationary by means of the hand-
wheel. When correctly adjusted, retighten screws D firmly.
Afterwards, the plunger (rib shaft) adjustment should be checked again as described
above.
Plunger (rib shaft) skip stitch timing
When sewing in skip stitch mode, the plunger (rib shaft) must perform one short stroke
and one long stroke alternately. The skip stitch eccentric must be adjusted for this.
(for part numbers, see spare parts list, page 10)
Turn the hand-wheel until the plunger (rib shaft) is in its rearmost position.
Remove the hand-wheel and gear wheel 221226.
Turn gear wheel 221227 until the plunger (rib shaft) is in its rearmost position.
Fit the hand-wheel with gear wheel 221226. When doing so, make sure that the main
shaft and gear wheel 221227 do not turn.
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