JUKI MOL-254 Engineer's Manual page 113

Adjustment Procedures
1. Loosen fixing screws
stretch the belt while turning the bracket and motor
clockwise making the position of the upper screw on this
side the center of rotation.
2. Check that the belt tension is adjusted so that the belt
sags approximately 0.6 mm when the center of the belt is
pressed with 2.94N force.
To attach the belt, lightly press the sprocket to the belt
to such an extent that the belt does not sag and the
proper tension is obtained.
in feed motor bracket
106
− −
Results of Improper Adjustment
○ I f t h e b e l t i s e x c e s s i v e l y
, and
stretched, the service life of belt
will be deteriorated or driving
torque will occur.
○ If the belt is insufficiently
stretched, tooth skipping of belt
will occur.