Teardown, Cleaning, and Reassembly of the Miscellaneous Parts of the Olympus BH-2 Microscope Frames
Revision 1
Page 8 of 45
Introduction
The microscopes in the Olympus BH-2 line have largely
been replaced in the professional and clinical world,
due to their advancing age and the lack of repair parts
from Olympus. A great many of these microscopes
were produced in their day, and because of this they
are readily available on the used market for very
reasonable prices. Thanks to their excellent build
quality and solid optical performance, these scopes are
now very popular with hobbyists, providing an
affordable and high-quality alternative to the Chinese-
made scopes prevalent today.
Problems that might be encountered when purchasing
one of these scopes is that various mechanical systems
may be stiff, sluggish, or even completely seized, due to
the decades-old grease in the microscope. Procedures
for servicing the major components of the Olympus
BH-2 stands are covered in other documents in this
series. This document describes the complete
teardown, cleaning/lubrication, and reassembly of the
various minor sections that are not covered elsewhere.
This should allow a hobbyist with reasonable
mechanical abilities to service these portions of the
applicable microscope stands.
Scope of this Document
This document describes the complete teardown,
cleaning/lubrication, and reassembly of the various
minor sections of the Olympus BHS (including BHSP),
BHSU, BHT (including BHTP), and BHTU microscopes,
covering the following components.
•
Viewing-Head Lock Screw (two versions)
•
Nosepiece Slide Mount (two versions)
•
Field Diaphragm Assembly (two versions)
•
Light Inlet Assembly
•
Light Exit Assembly (two versions)
Tools Needed
The tools listed in the sections below will be needed to
service
the
various
minor
sections
of
the
BHS/BHSU/BHT/BHTU stands.
•
Pliers, needle-nose
•
Pliers, soft jaw
•
Screwdriver set, JIS (item 7 of
•
Screwdriver set, slotted
•
Lens-Handling Suction Tool (item 9 of
•
Lens Spanner Tool, bent tips (item 8 of
A Few Words about JIS Screws
Screws with JIS heads are found in much of the older
equipment designed and manufactured in Japan. JIS
screws look very much like standard Phillips screws, but
they differ in that JIS screws were designed to not cam-
out under torque, whereas Phillips screws were
designed to intentionally cam-out as a means to limit
the torque applied to the fasteners. Because of this
crucial difference in the geometry of the two screw
types, JIS screws will be damaged by standard Phillips
drivers if too much torque is applied. JIS screws can
usually be identified by the presence of a single dot, or
by an “X”, stamped into one of the four quadrants of
the cross-point depression (see
Figure 1
–
Head of a typical JIS screw
Supplies Needed
The supplies listed in the sections below will be needed
to service the various minor sections of the
BHS/BHSU/BHT/BHTU stands.
•
Cleaning Solvent (see
section)
•
Cotton Swabs
•
Grease (see
section)
•
Pipe Cleaners
•
Tissues, oil-free (item 5 of
•
Lens Cleaning Solution (item 4 of
•
Lens Duster Bulb (item 11 of
•
Light Oil, PTFE (item 3 of
Recommended Lubricants
Plastilube® Brake Grease (medium consistency) can be
used on the various minor sections of the
BHS/BHSU/BHT/BHTU stands (item 1 of
.
Molykote 44 Light (item 2 of
) can be used
on the knurled field-adjustment ring of the Light Exit
Assembly. Both greases will remain serviceable for
many years to come.
Recommended Solvents
Some type of cleaning solvent will be needed to remove
the old grease from the various minor sections of the
BHS/BHSU/BHT/BHTU stands. Solvents that can be
used are acetone, diethyl ether, heptane, hexane,
mineral spirits, turpentine, and xylene.
Safety Considerations with Solvents
Regardless of which solvent is chosen, make sure that
adequate ventilation is present during the cleaning
process, and that any necessary personal protective
equipment is utilized to minimize exposure. Consult the
