JUKI LS-2342, Instruction Manual

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4-5. Needle-to-hook relation
Adjust the timing between the needle and the hook fol-
lowing the procedure described below.
1) Set the feed regulating dial to “0”.
2) Turn the handwheel to bring the needle bar to the
lowest position of its stroke, and loosen needle bar
connection screw
❶ .
* Determine the height of the needle bar.
3) The standard height of the needle bar is obtained
when a distance of 1.7 mm is provided between the
top end of the needle eyelet and blade point
❻ of the
hook when the needle bar ascends 2.4 mm from the
lowest position of its stroke.
* Determine the position of the hook.
4) Remove throat plate base cover ❷ . Loosen lower
bevel gear setscrews
❸
and
❹
and thrust support
setscrew ❽ .
5) In the state described in 3), loosen setscrew
❼
in the
hook driving shaft saddle and move the hook driving
shaft saddle to the right or left until a clearance of
dimension
A is provided between the blade point of
the hook and needle
❺
. After the adjustment, securely
tighten the screw.
6) Then, align the blade point of the hook with the center
of the needle, and tighten setscrew ❸ in the lower
shaft bevel gear.
7) Turn the handwheel clockwise and alternately tighten
setscrews
❹
little by little. (Never tighten either screw
only.)
8) Bringing the thrust support into close contact with the
lower bevel gear, tighten thrust support setscrew ❽ .
A
(mm)
LS-2342S, H 0 to 0.05
LS-2342S-7, 2342H-7 0 to 0.05
The operation panel could come in contact with the thread stand when tilting the machine head. To
protect the relevant parts from contact, shift the thread stand to a position at which the thread stand
does not interfere with the control panel.
To check the needle bar position as described in the aforementioned 3) [i.e., "...the needle bar ascend
by 2.4 mm from the lowest position of its stroke"], you may use the display of the main shaft rotation
angel under the "machine head adjustment mode" of the SC-922.
Increase the numerical value displayed when the needle bar is in its lowest position of its stroke
under the "machine head adjustment mode" by 25 degrees of an angle, the needle bar goes up by 2.4
mm. (When the needle bar ascends by 2.4 mm from its lowest position of its stroke, the main shaft
rotation angle is 25 degrees of an angle.)
* In the case of adjusting the needle-to-hook relation under the "machine head adjustment mode", do
not press
switch. Refer to "II-10. Adjustment of the machine head" in the Instruction Manual for
the SC-922 for the machine head adjustment mode.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the follow-
ing work after turning the power off and ascertaining that the motor is at rest.
❹ ❹ ❸
❸
❼
A
❺
❻
A
2.4mm
1.7mm
❷
❽
❶
Close contact