JUKI AMB-289 Engineer's Manual page 27

Adjustment Procedures
1. Remove hinge screw 2 of lever 1 and two screws 5 located
on the side of arm 4, and remove the unit.
2. Loosen four screws 7 fixing presser motor 6, and adjust the
backlash of worm gear 8.
(Caution) When adjusting the backlash, adjust at the position
where the centers of worm gear 8 and worm wheel
!3 almost align with each other.
Set the amount of backlash to 0.1 to 0.3 mm.
3. Apply enough JUKI grease B tube (white grease) to the whole
teeth section after cleanly wiping white grease gathered around
teeth of worm gear 8.
4. Turn the cross section attached to worm gear
screwdriver, loosen upper/lower sensor plate setscrews
sensor !2 when the clearance between the bottom face of
chuck 9 and the top surface of throat plate
adjust the sensor to the position where it goes off and lights,
and tighten upper/lower sensor plate setscrews
5. When the pedal is depressed at K57 Presser motor origin
compensation, the chuck goes up to sensor origin position
(17.6 mm), detects the sensor, and comes down to the top
end of tongue stopper 3.
At this time, make sure of the clearance of within 0 to 0.5 mm
between the top end of tongue stopper
of the chuck, perform fine adjustment with the panel, and set
the clearance to 0 mm.
8 with a
!1 of
!0 is 17.6 mm,
!1 .
3 and the bottom end
− 23 −
Results of improper Adjustment
™ When backlash is too close,
worm gear 8 is apt to be worn.
™ When the position is improper,
error occurs.