typical GC0303D - Adjusting Needle and Feed Mechanism Timing; Adjusting Rotary Hook Lubrication Amount

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23
4
5
6
6
1
2
7 8
A
A B
B
24
Needle timing advanced Standard Needle timing retarded
1
Oil amount
Small
Big
25. Adjusting the timing of needle and
feed mechanism (Fig. 23)
The standard timing is when the feed dog is
lowered from its highest position until it is flush
with the top of the needle plate ②, and the
needle eye ③ is also aligned horizontally with
the surface.
Adjust by changing the phases of feed cam and
eccentric wheel UD
1.Remove the rear cover
2.Turn the machine pulley in reverse direction,
set the second screw ④ on the gear of upper
shaft as reference mark, make the third screw
⑤ of eccentric wheel UD slightly lower than the
reference mark screw ④;
3.Continue to turn the machine pulley, set the
second screw ⑥ of eccentric wheel UD as
reference mark, make the third screw ⑦ of feed
cam slightly higher than the reference mark
screw ⑥.
4.If need a non-timing position, loosen the three
screws of eccentric wheel UD, adjust the
eccentric cam ⑧ in the direction of arrow (A) or
(B)
To increase the tension of thread, turn the
eccentric cam ⑧ to direction (A)
To avoid the needle bent, turn the eccentric cam
⑧ to direction (B)
5.After adjustment, tighten all of the screws.
26. Adjusting the rotary hook lubrication
amount (Fig. 24)
Tilt back the machine head, and turn the oil
adjustment screw ① to adjust the hook oiling
amount.