JUKI lbh-1790 series Engineer's Manual page 57

1. Removing the needle rocking motor
1) Remove the face plate section. (Refer to 5.- (5)) Disassembling/assembling the face plate section.)
2) Loosen setscrew 2 in needle bar rocking lever, rear 1.
3) Loosen two setscrews in thrust collar 3.
4) Draw out forward needle bar rocking shaft 4.
5) Remove three setscrews 6 in needle rocking motor installing base 5.
6) Lift upward the motor together with needle rocking motor installing base 5.
7) Tilt downward the rear side of needle rocking motor 7, move the position of needle bar rocking
lever, rear 1 in the direction of arrow mark and lift it upward.
8) Loosen setscrew 9 in motor lever 8, remove four fixing screws !0 in the needle rocking motor and
remove needle rocking motor 7.
9) Remove the motor cover and the rear cover, and draw out the wiring up to the relay p.c.b.
2. Assembling the needle rocking motor
1) Fix needle rocking motor 7 to needle rocking motor installing base 5.
2) Adjust motor lever 8 to the edge of the motor shaft and fix setscrew 9.
3) Set the needle rocking motor unit to the machine head.
4) Temporarily tighten needle rocking motor installing base 5 with three setscrews 6.
5) Insert needle bar rocking shaft 4 into the metal and fix it with thrust collor 3 at the position where
it can smoothly rock without thrust play.
(Caution) When inserting needle bar rocking shaft 4, insert it into the hole in needle bar rocking
lever, rear 1 as well.
6) Rock needle bar rocking lever, rear 1 by hand and fix three setscrews 6 in needle rocking installing
base 5 at the position where there is no torque.
7) Wire the cord of needle rocking motor 7 to the relay p.c.b.
8) Perform the origin adjustment of the needle rocking. (Refer to "4.-(1) Adjusting the needle rocking
origin".)
* Even when replacing the needle rocking sensor, remove the needle rocking motor unit in accordance
with the aforementined description.
Procedures of disassembling/assembling
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