SINGER 321D-241M-24 INDUSTRIAL SERGER - Manual (Page 14)

Replacing
Upper and
Lower Knife
Figure 11
Figure 12 (a)
11 Ultra High Speed Overedge and Safety Stitch Machine | Instruction Manual and Parts List
3.6
0.5~1.0mm
Top surface
of the needle
plate
4
6
6
4
3
8
7
1
4
5
2
Replacing the upper knife
1. Loosen screw ‘1’. Move lower
knife holder ‘2’ to the extreme left
position. Tighten screw ‘1’ temporar-
ily.
2. Remove screw ‘3’ and then upper
knife ‘4’.
To install a new upper knife, turn
the handwheel until the upper knife
holder reaches the lowest position of
its stroke. Overlap the cutting edges
of the upper anb lower knives by
0.5~1.0 mm according to the over-
edge width (Figure 11).
3. Overlap the cutting edges of the
upper and lower knives so that mid-
point ‘A’ on upper knife ‘4’ and the
midpoint of lower knife ‘6’ are
crossed (Figure 12). Loosen screw
Figure 12 (b)
Top surface
of the needle
plate
4
A
6
Adjusting overedge width
I. Loosen screw ‘1’ˈmove lower knife
holder ‘2’ all the way to the left and then
tighten the screw ‘1’ temporarily.
2. Loosen screw ‘7’ˈmove upper knife
clamp ‘8’ left or right as required. Install
upper and lower knives by referring to
"Replacing the upper knife" procedures 3
and 4.
‘1’. Make sure the upper and lower
knives mate positively. Then tighten
screw ‘1’.
4. Place a thread between the upper
and lower knives. Check the cutting by
turning the handwheel.
Replacing the lower knife
1. Loosen screw ‘1’. Move lower knife
holder ‘2’ to the extreme left position.
Tighten screw ‘1’ temporarily.
2. Loosen screw ‘5’ and remove lower
knife ‘6’. Install a new knife by referring
to "Replacing the upper knife” proce-
dures 3 and 4.
To install a new lower knife, the
cutting edge of the lower knife should
be flush with the top surface of the
needle plate.