SINGER 251 - Manual (Page 35)

35
TO REPLACE THE NEEDLE THREAD TAKE-UP
Replace the needle thread take-up in the following manner:
1. Make sure that the wearing plate J3 is in place
and undamaged on the face of the needle bar
crank, as shown in Fig. 52.
2. Place the needle thread take-up link G3 and take-
up H3 in the head of the machine so that the stud
W4, Fig. 52 in the center of the linkage slips into
the hole provided for it in the needle bar crank,
as shown in Fig. 52.
3. Slip the upper end of the take-up H3 through the
slot provided for it in the head of the machine.
4. Insert stud C3 through needle thread take-up
lever link G3 and into its hole into the machine
casting so that the flat on the stud faces the rear
of the machine. The mark D3 on the stud indicates
the position of this fiat. Fig. 52 shows the stud
with the mark D3 in the correct position. DO NOT
INSERT THE STUD TO ITS FULL DEPTH AT THIS
TIME. There should be about .010 inch to .015
inch side play of the take-up lever link G3 on the
stud, until final adjustment is made in Step 15.
5. Turn the set screw B3 inward lightly against the
flat on the stud C3. DO NOT TIGHTEN screw БЗ
until final adjustment is made in Step 15.
6. Turn machine pulley as required to make set
screw Y2 in needle bar crank accessible through
hole at A3, Fig. 53 in front of machine head.
7. Insert a screwdriver through this hole and, while
turning stud W4 by hand to find its flat, turn set
screw Y2 until it bears tightly upon the flat.
8. Turn screw Y2 back, just enough to "break It
loose."
9. Make certain that assembly F3 is firmly against,
but does not bind, wearing plate J3. Test for side
play by pushing take-up lever H3 gently right
and left; there should be .001 to .002 inch side
shake between lever and wearing plate.
10. Move thread take-up crank inward or outward
in needle bar crank, as required, to obtain clear­
ance.
11. Using wrench 146057, through same hole and
turning machine pulley as required, tighten hexa­
gon head screw Z2 lightly.
12. Loosen set screw Y2.
13. Securely tighten clamping screw Z2.
14. Securely tighten set screw Y2.
15. Push hinge stud C3 fully into machine casting and
securely tighten set screw B3.
16. Turn machine pulley slowly, by hand, at least
one complete revolution; testing take-up for bind­
ing, end shake and noise. If binding occurs, re­
check clearance between take-up and wearing
plate J3 and between hinge stud C3 and machine,
casting.
17. Replace guide bracket T in head of machine, as
shown in Fig. 52.
18. Replace presser bar pressure regulating thumb
screw X2, Fig. 51, page 33.
19. Replace and adjust upper needle bar bushing and
needle bar with their accessories, as instructed on
pages 18 and 33.
20. Replace and securely tighten arm hole plug A3.
21. Replace the face plate (see instructions at bottom
of page 18).