SINGER 251 - Manual (Page 33)

33
TO REMOVE AND REPLACE THE NEEDLE BAR
(See Fig. 51)
Fig. 51. Removing and Replacing
Needle Bar and Presser Bar
Remove the needle bar in the following manner:—
1. Remove needle and needle set screw (or needle
clamp).
2. Remove face plate.
3. Loosen clamping screw M.
4. Loosen screw R2 sufficiently to allow needle bar
to pass, then slip needle bar up through both
needle bar bushings and out of machine.
NOTE: If it becomes necessary to remove upper needle
bar bushing N, first remove screw R2 and take-up lever
oil guard W2. Then loosen set screw P and drive
bushing N down and out of head of machine. Use a
13/32 Inch driving pin.
Before replacing needle bar, replace upper needle
bar bushing N, by driving it down into hole provided
for it in head of the machine. Make certain top of
bushing N is level with top of arm. Tighten set screw P.
Replace needle bar in the following manner*.—
1. Slip needle bar down through both bushings in
head of the machine. Tighten screw M.
2. Replace needle clamp and needle. See page 8.
3. Set needle bar at correct height and replace face
plate, as instructed in last paragraph on page 18.
4. Replace oil guard W2 and fasten it securely to
bushing with set screw R2.
TO REMOVE AND REPLACE THE PRESSER BAR
To remove the presser bar:-
1 .
2
.
Remove presser foot and face plate.
Remove presser bar pressure regulating thumb
screw, X2, w ith pressure bar guide from head
of the machine.
3. Loosen clamping screw V about one turn (just
enough to make it loose). Loosen screw A5 and
slip guide bracket T up off presser bar and out
of machine.
4. Slide presser bar up through lifting bracket U,
Fig. 51 and bushing and out of machine.
To replace the presser bar:—
1. Slip presser bar down through lifting bracket U,
Fig. 51 and lower presser bar bushing.
2. Replace guide bracket T as shown in Fig. 51.
3. Replace presser foot.
4. Replace presser bar pressure regulating thumb
screw X2 with presser bar guide.
5. Set the presser bar at the correct height, as in­
structed on page 20.
6. Tighten screw V.
7. Tighten screw A5; making sure that slack thread
regulator B5 just clears the casting. Replace face
plate, as instructed on page 18.