SINGER 251 - Manual (Page 18)

в
1 8
ТО SET THE NEEDLE BAR AT THE CORRECT HEIGHT
нк)!
UPPER
TIMING
NEEDLE BAR
AT
LOWEST POINT
I
м/с 25I-I
.484 inch
M/C25I-2
and 25I-3
.195 inch
UPPER
TIMING
MARK
NEEDLE BAR
vAT LOWEST
POINT
mmms
Fig. 28. Setting Needle Bar Height on Machines with Timing
Marks Aligned with UPPER Needle Bar Bushing
PREPARATION;
Remove face plate, slide plate and throat plate. See
that needle is correctly set in needle bar, as instructed
on page 8.
NOTE:
FOR MACHINES ON WHICH TIMING MARKS SHOULD
ALIGN WITH UPPER NEEDLE BAR BUSHING-
Top of bushing A, Fig. 28 must be flush with top of
casting, as shown in Fig. 28. To reset bushing, loosen
screw В and raise or lower bushing, as required.
FOR MACHINES ON WHICH TIMING MARKS SHOULD
ALIGN WITH LOWER NEEDLE BAR BUSHING-
Lower end of bushing K, Fig. 29 must be set as
shown in Fig. 29. To reset bushing, loosen screw L.
Fig. 29. Setting Needle Bar Height on Machines with Timing
Marks Aligned with LOWER Needle Bar Bushing
CHECK;
When needle bar is at its lowest point (during rota­
tion of machine pulley), UPPER TIMING MARK on
needle bar should be level with lower end of bushing.
Check timing of hook as instructed on page 21.
SETTING:
Loosen clamping screw C, Figs. 28 and 29. Raise or
lower needle bar so that UPPER TIMING MARK is level
with
lower end of bushing. Then securely tighten
screw C.
Replace throat plate and slide plate.
When replacing the face plate, make certain that
the screw holes in the face plate gasket are aligned
with
the respective screw holes in the face plate;
avoiding injury to the gasket and consequent oil
leakage.