Adjusting Height Of The Needle Bar; Adjusting The Needle-To-Hook Timing And The Needle Guard - JUKI LZ-2280A Series Instruction Manual

4-10. Adjusting height of the needle bar

WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
2
1
1. Thickness of the semicircle plate ❷ is different from that of the throat plate. So, be sure to use
the semicircle plate ❷ when adjusting the height of the needle bar.
Be sure to perform the adjustment with zigzag width set to zero and with the needle positioned
at the center of the zigzag stroke.
2. For the LZ-2280AA, timing gauge D should be used.
For the LZ-2280AB, -2284A* and -2287A, timing gauge E should be used.

4-11. Adjusting the needle-to-hook timing and the needle guard

WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
2
1
(2) Confirmation
In the case of the maximum needle throwing width (adjustment at the time of shipment: LZ-2280AA: 4 mm;
Other models: 8 mm), check to be sure that the distance from the top end of the needle eyelet to the blade
point of the hook is 0.2 to 0.5 mm while the needle throws to the left.
* If the zigzag width of 10 mm is used or the shape of indented part of the needle is different from that of
indented part of the needle at the time of delivery, re-adjust the height of the needle bar.
(3) Adjusting the needle guard
1) Maximize the zigzag width. Bend the needle guard to adjust so that the needle does not come in contact
with the blade point of the both at the leftmost and rightmost positions of the zigzag stroke. At this time,
adjust the clearance provided between the needle and the blade point of the hook to 0 to 0.05 mm.
2) The needle guard functions to keep the needle away from the blade point of the hook, thereby preventing
damage to the blade point of the hook. Whenever you have replaced the hook with a new one, be sure to
adjust the position of the needle guard.
When thread breakage has occurred, there is a case where thread is caught in the hook.
Be sure to perform sewing after removing the thread caught in the hook.
❷
❶
0 to 0.05 mm
1) Set the zigzag width to "0". Bring the needle to
the center of the zigzag stroke.
2) Remove the presser foot, throat plate, semicircle
plate ❷ and feed dog.
Place half-moon shaped plate ❷ on the throat-
3)
plate installing surface of the bed. Loosen set-
screw ❶. Adjust so that the distance from the top
surface of the half-moon shaped plate ❷ to the
bottom end of the needle bar equals to the height
of timing gauge 1.
(1) Positioning the hook
1) After the completion of the adjustment of the
needle bar height, adjust the hook using timing
gauge 2 so that the blade point of the hook is
aligned with the center of the needle.
2) At this time, the blade point of the hook should
slightly come in contact with the needle when the
needle guard does not touch the needle.
– 17 –