Pfaff 238-0 User Manual

Thread regulator J (Fig. 28) Is mounted on the presser bar guide collar and moves up
and down with the presser bar as the sewing foot passes over Irregularities In thickness.
By so doing, It adapts the thread consumption to the varying thicknesses of the ma
terial being sewn. As a result of this action, the check spring has to take up less thread
when thicker portions of the material pass under the sewing foot.
Thread regulator J can be adjusted vertically after loosening screw d (Fig. 28). By
setting the thread regulator higher or lower the amount of thread to be controlled by
the thread check spring can be adjusted within certain limits. It Is recommended to
correlate the thread regulator and tension barrel settings so that the thread check
spring not only takes up the proper amount of thread, but also pulls the thread up
wards perpendicularly.
Once you are familiar with the functions performed by both the check spring and the
thread regulator, you will be able to make the proper adjustment right away without
resorting to trial-and-error methods.
The thread check spring is timed correctly If it Is through acting when the needle reach
es the goods. Since the take-up lever of the Pfaff 238 makes a rather long stroke, it
may be
necessary to Increase the stroke of the thread check spring somewhat so that
it will still exert a slight pull on the thread when the needle enters the material.
25. Timing the Sewing Hook
To time the sewing hook correctly, we recommend that you use a needle rise gauge
which can be obtained from us under Order Nos. 880136/01 and 880137/00.
Begin by removing the needle plate and setting lever H In notch II and knob G on "0"
(Fig. 20).
Rotate the balance wheel until the needle has reached the lowest point of Its
stroke. Slip both the needle rise gauge (5/64", or 2.0 mm, thick and the clamp onto the
needle bar, push the clamp up against the gauge until the latter contacts the needle
bar frame, and tighten the clamp screw securely (Fig. 29).
Then pull out the gauge and cautiously turn the balance wheel until the clamp contacts
the needle bar frame (Fig. 30). Loosen set screws K and T (Figs. 29 and 30, respectively)
and rotate the sewing hook on Its shaft until Its point Is opposite the center line of the
needle.
At the same time, set the hook as close to the needle as possible, the proper clearance
between both parts being .004", or 0.1 mm (Fig. 31).
40
From the library of: Superior Sewing Machine & Supply LLC

Pfaff 238-0 Specifications

General

Brand	Pfaff
Model	238-0
Category	Sewing Machine
Language	English