B. Mechanical
Maintenance
4. Adjusting the tension of the coarse focus knob.
The collar to adjust the tension of the coarse focus knob (Fig. 1) is situated between
the coarse focus knob (9) and the arm (12).
The tension of the coarse focus is pre adjusted by the manufacturer. The optimum
tension point is that which permits the coarse focus knob to move as smoothly as
possible, without the head (7) sliding down by itself.
a. To adjust tension first loosen the screw situated in one of the four orifices of the
collar with a 2mm hexagonal key.
b. To tighten the tension of the coarse focus knob, turn the collar in the clockwise. To
loosen it, turn anti clockwise.
c. Tighten
hexagonal
screw.
5. Adjusting the rack stop.
The 40X objective use a retractable
security system to avoid damage to the
slide or to the front of the lens should they
come into contact. An additional security
measure is the security rack stop screw
that regulates the descending movement
of the head. It is adjusted by the
manufacturer for the observation of
standard slides with a cover slip 0.17mm
thick; but for the observation of other types
of slides, readjustment may be necessary.
Tensión
adjustment
collar
Set screw
Screw used to
adjust the height
of the head
a. Firstly, loosen the rack stop
screw. (Fig. 1)
b. Next, unscrew the adjustment
screw. (Fig. 1)
c. Turn the fine focus knob (10)
until at mid point (not applicable
for SFC-3A).
Fig. 1
d. Focus on the slide only using the coarse focus control (9) with the 4X objective (5)
firstly, and then the 10X.
e. Tighten the adjustment screw only until firm, so that the head (3) cannot descend.
f.
Tighten the rack stop screw.
-6-
