Pfaff 3334 User Manual

loosen the nut on the knife pinion stud brocket set screw (Fig. 49), and take
out this screw. Next, remove the knife pinion stud bracket and the knife
assembly.
There is a possibility of getting at the knives without removing the knife
holder pinion stud bracket. To do this, loosen the small hexagon screw b
(Fig. 50) on the feed plate, and pull the feed plate up out of its mount.
After removing the four needle plate set screws, both the needle plate and
the trimming mechanism can be pulled forward out of the machine.
The knives
are secured to the knife carrier only by screw a (Fig. 50). Take
out this screw and sharpen the knives with a knife grinder, or replace them
by new ones.
Fig. 50 Changing the knives
When you sharpen the knives, take care that the cutting edge is not simply
polished, but really sharpened, and that the tips
are well polished and
free from jags (Fig. 51).
In replacing the knives, make sure they fit in the knife
carrier groove
correctly. Then tighten screw a securely. The meshing teeth of both the rack
and the pinion are spotted (Fig. 49) so that the knife bar need not be read
justed after the knife assembly has been replaced. To replace the knife
assembly in the machine, simply reverse the above procedure.
To ensure that the trimming mechanism will function correctly, coordinate
the functions of both needle thread tensions properly. The upper needle
thread tension normally must be lighter, while the lower needle thread tension
should be tighter.
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From the library of: Superior Sewing Machine & Supply LLC

Pfaff 3334 Specifications

General

Brand	Pfaff
Model	3334
Category	Sewing Machine
Language	English