(D) Adjustment - Sharp TMV Series Service And Parts Manual

(D) Adjustment:

(a) Adjustment of Backlash of Leadscrew:
After a certain period of time, a clearance is developed between the leadscrew and its nut
due to frictions. Positioning accuracy will become impossible. Therefore, the nut must be
adjusted so as to keep a proper tension between itself and the leadscrew.
1. Adjustment of cross leadscrew (Vide Figure 25):
a. Turn counterclockwise the crank (F) and move the saddle seat to the foremost
position of knee.
b. Remove the two setting pins (H) of the front bearing bracket (G) and take off the
four socket HD cap screw (I).
c. Support the cross feed bearing bracket (G) and turn clockwise the crank (F) so that
the bracket will be separated from the knee with a certain distance between them
(as shown in Figure 26, the distance must be longer than the length of the adjusting
tool).
d. Insert the larger end of clearance adjusting tool into the knee and turn the locking
nut (J) one round Counterclockwise. Reverse the adjusting tool and insert the
smaller end into the knee. Turn the nut (K) clockwise and lock it up.
e. Turn clockwise and Counterclockwise the crank (F) and measure a clearance of
approximately 3-4 graduations (0.06mm-0.08mm or 0.003-0.004") on the dial.
Lock up (J) consequently.
f. Turning counterclockwise the leadscrew into the knee until the front bearing
bracket seat gets in contact with the knee. Insert the two setting pins (H) and lock
up tightly the four cap screw (I) of the bearing bracket.
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