Olympus BH2 Series Complete Teardown, Cleaning, And Reassembly - Page 28
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While snugging the brass shaft mount, periodically
move the coarse-focus knob back and forth a bit such
that the brass shaft mount moves with it (without the
stop pins hitting), to make sure that the motion of the
knob/brass shaft mount does not get stiff as you tighten
the brass shaft mount. If you begin to feel abnormal
stiffness, loosen the tension-adjustment knob on the
right-hand side of the pillar arm to alleviate the
stiffness.
If loosening the tension-adjustment knob
does not alleviate the stiffness, proceed very carefully
from here, as the spring is likely improperly positioned
and is being pinched by the brass shaft mount. If this is
the case, loosen the coarse-focus knob until the brass
shaft mount disengages from the threaded coarse-focus
shaft, and re-check the installation of the coil spring.
Repeat the above installation procedure until the
coarse-focus knob moves freely when the brass shaft
mount is snugged to hand tight.
While not allowing the brass shaft mount to rotate, grip
the brass shaft mount with non-marring pliers and
rotate the right-hand coarse-focus knob clockwise until
it is a bit tighter than hand tight, then release the pliers
grip on the brass shaft mount. Once again, spin the
coarse-focus knob on the right-hand side back-and-
forth slightly to make sure that it still rotates freely. As
above, if excessive friction is encountered, loosen the
tension-adjustment knob to see if it alleviates the issue.
If it does not, remove the brass shaft mount and repeat
the installation, until the coarse-focus knob moves
freely with the brass shaft mount fully tightened.
Once the brass shaft mount has been hand-tightened
and the action of the coarse-focus knob has been found
to be acceptable, use a 1.5mm Allen tool or driver to
reinstall and tighten the two perpendicular M3X5
setscrews into the brass shaft mount, to lock this piece
onto the coarse-focus shaft (see
Figure 86 – Reinstall setscrews to lock brass shaft mount
Complete Teardown, Cleaning, and Reassembly of the Olympus BH-2 Coaxial Focus Mechanism
Figure
86).
Test the Pre-Focus Stop Mechanism
Before proceeding further with reassembly of the
coaxial focus mechanism, you should verify proper
operation of the pre-focus stop mechanism. To do this,
loosen the pre-focus lock collar on the left-hand side of
the pillar arm and rotate the coarse-focus knob
clockwise (such that the brass shaft mount on the
opposite side moves counterclockwise) a bit.
rotate the pre-focus lock collar clockwise to set the pre-
focus stop. Verify that the coarse-focus knob cannot be
further rotated in the clockwise direction but can be
rotated counterclockwise (do not exceed approximately
¼ turn). Rotate the coarse-focus knob counterclockwise
approximately one quarter turn from the stop position,
to load the coil spring beyond the pre-load, and then
loosen the pre-focus lock collar. When you loosen the
pre-focus collar, you should hear a positive "slap" sound
caused by the two stop pins hitting together when the
rotating lock ring spins around to relax the coil spring.
Snug the pre-focus lock collar once again and verify that
the coarse-focus knob cannot be rotated clockwise but
can be rotated counterclockwise (once again, do not
exceed approximately ¼ turn).
mechanism is working correctly if these conditions are
met, and if this is the case you can proceed with
reassembly of the coaxial focus mechanism.
If on the other hand the coarse-focus knob can be
rotated a noticeable amount in the clockwise direction
from the point where the pre-focus lock collar was set,
or if the slapping sound is not heard (or is not vigorously
heard) when the pre-focus lock collar is released, this
indicates that the pre-focus stop mechanism is not
working properly.
The coil spring may have been
improperly pre-loaded or there may be grease or other
contamination on one or more of the various pre-focus
stop components, preventing the rotating lock ring from
moving freely when the pre-focus lock collar is
loosened. If this is the case, disassemble the pre-focus
lock mechanism and correct whatever is wrong, then
carefully reassemble per the description above. Once
the pre-focus stop mechanism passes the pre-focus stop
verification test before described above, you may
proceed with the reassembly of the coaxial focus
mechanism.
Reinstall Stop Screw for the Pre-Focus Lock Collar
Rotate the pre-focus lock collar on the left-hand side of
the pillar arm clockwise, to set the pre-focus stop.
Using a small (3mm) slotted screwdriver, reinstall the
slotted M3X6 headless shoulder screw into the tapped
hole in the pillar arm casting, just below the pre-focus
lock collar (see
Figure
87).
Now
The pre-focus stop
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