typical GC2605, Operating Instructions & Parts Manual

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28
27
29
6. A dj ust ment
6.1 Timing between the needle and the rotating hook
6.1.1 Adjusting the position of needle bar (Fig.27)
Turn the balance wheel to locate the needle bar at
its lowest position, remove the rubber plug in face plate
A, then loosen the needle bar connecting stud clamping
screw B and move the needle bar C vertically to make
the centre of needle eye D concidence with inside
surface E of bobbin case holder. Tighten clamping
screw B, put on the plug.
Note: when sewing light material and using nylon,
polyester fabrics, the needle timing position is 0.5mm
above the standard timing position.
6.1.2 Adjusting the rotating hook point timing with the
needle.
Turn the balance wheel to locate the needle bar at
its lowest position, and when the needle bar is lifted
again at 2.5mm from its lowest position, the rotating
hook point D should coincides with needle center line
C, and hook point D is 1.2mm above upper edge E of
needle eye.(See Fig.28)
When adjusting the rotating hook point timing,
make sure the clearness between notch bottom of needle
D and hook point C must be kept approx.0.05mm(see
Fig.29).
6.1.3Dismantling and installing the rotating hook(F.30)
Lift the presser foot and lift the needle bar to its
highest position, remove the slide ring, the bobbin case,
back-up ring, throat plate, the bobbin case holder
position bracket cap, feed dog throat plate, bobbin case
holder position bracket, then turn the balance wheel
and loosen three set screw D of the rotating hook,
At last, take it down slowly with hand.
Installing the rotating hook can be done in reverse
sequence.
6.1.4 Adjusting the clearance between rotating hook
inner surface and the bobbin case holder position
bracket(Fig.30)
The projecting flange of position bracket A should
be engaged in notch B of the bobbin case holder, and
maintain a chearance of 0.5-0.7mm between projecting
flange top and bottom of notch while installing.
A
B
C
D
E
F
H
C
D
0.05mm
C
D
E
B
1. 2mm
2. 5mm
30
A
D
B
0.5-0.7mm