Olympus BH2-BI30 Installation instructions

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 1 of 34
Complete Teardown, Cleaning, and
Reassembly of the Olympus BH2-BI30
Binocular Viewing Head
(Revision 1)
Copyright © 2017 Carl Hunsinger
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Revision History
Revision
Description of Changes
Date
1
*** Initial Release ***
9-19-2017

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 2 of 34
Table of Contents
Introduction ............................................................................................................................................................................ 7
Scope of this Document.......................................................................................................................................................... 7
Before Attempting Your Own Service..................................................................................................................................... 7
Common Problems with the BH2-BI30 Head.......................................................................................................................... 7
Interocular-Distance Slide is Stiff or Seized ........................................................................................................................ 7
Focus Ring on Left-Hand Ocular Tube is Stiff or Seized ...................................................................................................... 7
Internal Optics are Dirty...................................................................................................................................................... 7
Optical Alignment is Poor ................................................................................................................................................... 8
Left-Hand and Right-Hand Side Designations......................................................................................................................... 8
Tools Needed .......................................................................................................................................................................... 8
Electric Heat Gun .................................................................................................................................................................... 8
A Few Words about JIS Screws ............................................................................................................................................... 8
Disassembling the BH2-BI30 Viewing Head............................................................................................................................ 8
Supplies Needed ..................................................................................................................................................................... 9
Recommended Solvents ......................................................................................................................................................... 9
Safety Considerations with Solvents....................................................................................................................................... 9
Solvent Compatibility with Parts and Finishes........................................................................................................................ 9
Recommended Lubricants ...................................................................................................................................................... 9
Label Parts for Identification and Reassembly........................................................................................................................ 9
Servicing the BH2-BI30 Binocular Viewing Head .................................................................................................................... 9
Remove the Helical Focus Ring (Left)................................................................................................................................ 10
Remove the Plastic Finger Grip (Left) ............................................................................................................................... 10
Remove the Plastic Finger Grip (Right) ............................................................................................................................. 11
Remove the Graduated Center Cover............................................................................................................................... 11
Remove the Frame Assembly from the Main Housing ..................................................................................................... 12
Remove Mounting Disk Assembly from Main Housing .................................................................................................... 12
Reinstall Mounting Disk Assembly onto Main Housing .................................................................................................... 13
Remove the Tension Springs for the Follower Keys ......................................................................................................... 13
Remove the Follower Keys................................................................................................................................................ 14
Clean Inner Tubes and Regrease the Helical Focus Ring................................................................................................... 14
Remove the Ocular Slide Assembly (Left)......................................................................................................................... 17
Remove the Ocular Slide Assembly (Right)....................................................................................................................... 18
Remove the Brass Pivot Lever........................................................................................................................................... 18
Clean the Various Mechanical Parts ................................................................................................................................. 19
Remove the P3/P4 Prism Mount ...................................................................................................................................... 20
Reinstall the P3/P4 Prism Mount...................................................................................................................................... 21
Clean the Various Optical Components ............................................................................................................................ 21
Lubricate the Various Slide Parts ...................................................................................................................................... 23
Reinstall the Ocular Slide Assembly (Left) ........................................................................................................................ 25
Reinstall the Ocular Slide Assembly (Right) ...................................................................................................................... 26
Grease the Follower-Key Slots in the Front Frame ........................................................................................................... 27
Reinstall the Follower Keys ............................................................................................................................................... 27
Reinstall the Tension Springs for the Follower Keys......................................................................................................... 27
Reinstall the Frame Assembly into the Main Housing ...................................................................................................... 29
Reinstall the Graduated Center Plate ............................................................................................................................... 29
Reinstall the Plastic Finger Grips....................................................................................................................................... 30
Reinstall the Helical Focus Ring (Left) –Most Accurate.................................................................................................... 31
Reinstall the Helical Focus Ring (Left) –Less Accurate ..................................................................................................... 32
Reinstall the Black Trim Ring for Ocular Tube (Right)....................................................................................................... 32
Ready for Service .................................................................................................................................................................. 33

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 3 of 34
Original Olympus Documentation ........................................................................................................................................ 33
How to Contact the Author................................................................................................................................................... 33
Appendix 1 ............................................................................................................................................................................ 34
Sources for Replacement Tools and Supplies Referenced in this Document ....................................................................... 34
Table of Figures
Figure 1 –The Jentsch style BH2-BI30 viewing head.............................................................................................................. 7
Figure 2 –Head of a typical JIS screw ..................................................................................................................................... 8
Figure 3 –Loosen set screws securing helical focus ring (left) ............................................................................................. 10
Figure 4 –Remove helical focus ring from ocular tube (left) ............................................................................................... 10
Figure 5 –Screws securing finger grip to the slide (left)....................................................................................................... 10
Figure 6 –Remove screws securing finger grip (left)............................................................................................................ 10
Figure 7 –Remove front screw from finger grip (left).......................................................................................................... 10
Figure 8 –Remove finger grip from ocular tube (left).......................................................................................................... 10
Figure 9 –Screws securing finger grip to slide (right)........................................................................................................... 11
Figure 10 –Remove screws securing finger grip (right)........................................................................................................ 11
Figure 11 –Remove front screw from finger grip (right)...................................................................................................... 11
Figure 12 –Remove finger grip from ocular tube (right)...................................................................................................... 11
Figure 13 –Remove screws securing center cover (top)...................................................................................................... 11
Figure 14 –Remove screws securing center cover (bottom) ............................................................................................... 11
Figure 15 –Remove the center cover from the frame ......................................................................................................... 12
Figure 16 –Screws securing front frame to the main housing............................................................................................. 12
Figure 17 –Remove screws securing front frame to housing .............................................................................................. 12
Figure 18 –Remove frame assembly from main housing..................................................................................................... 12
Figure 19 –Apply tape to mark placement of mounting disk............................................................................................... 12
Figure 20 –Remove screws securing mounting disk assembly ............................................................................................ 12
Figure 21 –Remove the mounting disk assembly ................................................................................................................ 13
Figure 22 –The mounting disk assembly.............................................................................................................................. 13
Figure 23 –Place the mounting disk assembly into position................................................................................................ 13
Figure 24 –Secure the mounting disk assembly in position................................................................................................. 13
Figure 25 –The tensions springs for the follower keys ........................................................................................................ 13
Figure 26 –Relieve the pre-load on the straight spring ....................................................................................................... 13
Figure 27 –Remove the screw securing the straight spring................................................................................................. 14
Figure 28 –Remove the straight spring ................................................................................................................................ 14
Figure 29 –Remove the screw securing the bent spring...................................................................................................... 14
Figure 30 –Remove the bent spring..................................................................................................................................... 14
Figure 31 –Remove the follower key (right) ........................................................................................................................ 14
Figure 32 –Remove the follower key (left) .......................................................................................................................... 14
Figure 33 –Remove helical/polished inner tubes (left)........................................................................................................ 15
Figure 34 –Remove grease from inner tube (left) ............................................................................................................... 15
Figure 35 –Unscrew helical tube from the inner tube (left) ................................................................................................ 15
Figure 36 –Clean old grease from the outer helicoid threads ............................................................................................. 15
Figure 37 –Clean grease from threads of inner tube (left) .................................................................................................. 15
Figure 38 –Apply fresh grease to the outer helicoid threads .............................................................................................. 15
Figure 39 –Apply fresh grease to inner helicoid threads (left) ............................................................................................ 16
Figure 40 –Thread the helical tube into the inner tube (left) .............................................................................................. 16
Figure 41 –Remove grease from the ocular tube (left)........................................................................................................ 16

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 4 of 34
Figure 42 –Reinstall the inner / helical tubes (left).............................................................................................................. 16
Figure 43 –Remove black trim ring from ocular tube (right) ............................................................................................... 16
Figure 44 –Remove the fixed sleeve/inner tubes (right) ..................................................................................................... 16
Figure 45 –Remove grease from the inner tube (right)....................................................................................................... 17
Figure 46 –Remove grease from the ocular tube (right) ..................................................................................................... 17
Figure 47 –Reinstall the fixed sleeve / inner tube (right) .................................................................................................... 17
Figure 48 –Remove screws securing dovetail block (left).................................................................................................... 17
Figure 49 –Remove dovetail block from the frame (left) .................................................................................................... 17
Figure 50 –Remove the ocular slide assembly (left) ............................................................................................................ 17
Figure 51 –The ocular slide assembly (left).......................................................................................................................... 18
Figure 52 –Remove screws securing dovetail block (right).................................................................................................. 18
Figure 53 –Remove dovetail block from frame (right)......................................................................................................... 18
Figure 54 –Remove the ocular slide assembly (right).......................................................................................................... 18
Figure 55 –The ocular slide assembly (right) ....................................................................................................................... 18
Figure 56 –Remove screw holding brass pivot lever in place .............................................................................................. 18
Figure 57 –Remove brass pivot lever from the frame ......................................................................................................... 19
Figure 58 –Clean old grease from the brass pivot lever ...................................................................................................... 19
Figure 59 –Clean grease from pivot-lever bearing surface.................................................................................................. 19
Figure 60 –Clean grease from the lower dovetail bevels..................................................................................................... 19
Figure 61 –Clean old grease from upper sliding surfaces .................................................................................................... 19
Figure 62 –Clean old grease from bevels of slide (right) ..................................................................................................... 19
Figure 63 –Clean old grease from bevels of slide (left)........................................................................................................ 20
Figure 64 –Clean old grease from back of slide (right) ........................................................................................................ 20
Figure 65 –Clean old grease from back of slide (left) .......................................................................................................... 20
Figure 66 –Clean old grease from both dovetail blocks....................................................................................................... 20
Figure 67 –Remove screws securing the P3/P4 prism mount ............................................................................................. 20
Figure 68 –Remove P3/P4 prism mount with prisms .......................................................................................................... 20
Figure 69 –The P3/P4 prism mount with P3 and P4 prisms................................................................................................. 21
Figure 70 –Place P3/P4 prism mount into position on frame.............................................................................................. 21
Figure 71 –Reinstall screws to secure P3/P4 prism mount.................................................................................................. 21
Figure 72 –Clean face of prism P1 in mounting dovetail ..................................................................................................... 21
Figure 73 –Clean the face of P2 prism in the main housing................................................................................................. 21
Figure 74 –Clean three faces of P3/P4 prisms (view 1) ....................................................................................................... 22
Figure 75 –Clean three faces of P3/P4 prisms (view 2) ....................................................................................................... 22
Figure 76 –Remove sleeve/inner tube from ocular tube (right).......................................................................................... 22
Figure 77 –Clean face 1 of the P5 prism (right).................................................................................................................... 22
Figure 78 –Clean face 2 of the P5 prism (right).................................................................................................................... 22
Figure 79 –Lightly grease polished inner tube (right).......................................................................................................... 22
Figure 80 –Reinstall inner tube/sleeve into ocular tube (right)........................................................................................... 23
Figure 81 –Remove helical/inner tubes from ocular tube (left) .......................................................................................... 23
Figure 82 –Clean face 1 of the P6 prism (left)...................................................................................................................... 23
Figure 83 –Clean face 2 of the P6 prism (left)...................................................................................................................... 23
Figure 84 –Lightly grease the polished inner tube (left)...................................................................................................... 23
Figure 85 –Reinstall helical/inner tubes into ocular tube (left) ........................................................................................... 23
Figure 86 –Apply grease to lower dovetail bevels of frame ................................................................................................ 24
Figure 87 –Apply grease to upper sliding surfaces of frame................................................................................................ 24
Figure 88 –Apply grease to pivot-lever bearing surface of frame ....................................................................................... 24

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 5 of 34
Figure 89 –Apply grease to the hole and slots in pivot lever............................................................................................... 24
Figure 90 –Embed brass pivot lever into grease on the frame............................................................................................ 24
Figure 91 –Reinstall pivot-shaft screw to secure pivot lever............................................................................................... 24
Figure 92 –Apply grease to rear bearing surfaces (right)..................................................................................................... 25
Figure 93 –Apply grease to rear bearing surfaces (left)....................................................................................................... 25
Figure 94 –Seat lower bevel into the bottom dovetail (left) ............................................................................................... 25
Figure 95 –Index pin engaged with brass pivot lever (left).................................................................................................. 25
Figure 96 –Apply grease to the upper bevel (left) ............................................................................................................... 25
Figure 97 –Place the dovetail block into position (left) ....................................................................................................... 25
Figure 98 –Reinstall screws to secure dovetail block (left).................................................................................................. 26
Figure 99 –Seat lower bevel into bottom dovetail (right).................................................................................................... 26
Figure 100 –Index pin engaged with brass pivot lever (right) ............................................................................................. 26
Figure 101 –Apply grease to the upper bevel (right) ........................................................................................................... 26
Figure 102 –Place the dovetail block into position (right) ................................................................................................... 26
Figure 103 –Reinstall screws to secure dovetail block (right).............................................................................................. 26
Figure 104 –Grease two slots in the top of front frame ...................................................................................................... 27
Figure 105 –Position ocular slide to center hole in slot (left) .............................................................................................. 27
Figure 106 –Reinstall the follower key into the slot (left) ................................................................................................... 27
Figure 107 –Position ocular tube to center hole in slot (right)............................................................................................ 27
Figure 108 –Reinstall the follower key into the slot (right) ................................................................................................. 27
Figure 109 –Hook straight spring over follower key (right) ................................................................................................. 27
Figure 110 –Align coil of straight spring with hole (right).................................................................................................... 28
Figure 111 –Secure the straight spring with screw (right)................................................................................................... 28
Figure 112 –Hook bent spring over follower key (left) ........................................................................................................ 28
Figure 113 –Align coil of bent spring with hole (left)........................................................................................................... 28
Figure 114 –Secure the bent spring with screw (left).......................................................................................................... 28
Figure 115 –Pre-load the two tension springs ..................................................................................................................... 28
Figure 116 –Slide the frame assembly into the main housing............................................................................................. 29
Figure 117 –Position frame so holes line up with housing .................................................................................................. 29
Figure 118 –Secure frame assembly into the main housing................................................................................................ 29
Figure 119 –Spread the two ocular tubes apart .................................................................................................................. 29
Figure 120 –Position center plate to align with holes in frame........................................................................................... 29
Figure 121 –Secure the plate with two screws (top) ........................................................................................................... 29
Figure 122 –Secure the plate with two screws (bottom)..................................................................................................... 30
Figure 123 –Set the ocular tubes to their maximum spacing .............................................................................................. 30
Figure 124 –Place the finger grip into position (left) ........................................................................................................... 30
Figure 125 –Reinstall front screw into the finger grip (left) ................................................................................................ 30
Figure 126 –Reinstall back screws into the finger grip (left)................................................................................................ 30
Figure 127 –Place the finger grip into position (right)......................................................................................................... 30
Figure 128 –Reinstall front screw into the finger grip (right) .............................................................................................. 31
Figure 129 –Reinstall back screws into the finger grip (right) ............................................................................................. 31
Figure 130 –Place helical focus ring onto ocular tube (left) ................................................................................................ 31
Figure 131 –Tighten set screws to secure helical focus ring................................................................................................ 31
Figure 132 –Loosen set screws securing helical focus ring.................................................................................................. 32
Figure 133 –Align the zero-diopter marking with white dot ............................................................................................... 32
Figure 134 –Adjust helical focus tube for equal tube lengths ............................................................................................. 32
Figure 135 –Apply spots of adhesive to ocular tube (right)................................................................................................. 32

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 6 of 34
Figure 136 –Place trim ring over the ocular tube (right) ..................................................................................................... 33
Figure 137 –Press trim ring into adhesive to seat it (right) ................................................................................................. 33
Figure 138 –The Olympus BH2-BI30 repair manual............................................................................................................. 33
Figure 139 –The Olympus BH2 (BHS) repair manual ........................................................................................................... 33

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 7 of 34
Introduction
The biological microscopes in the Olympus BH-2 line
(BHS, BHSU, BHT, and BHTU) 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 are they
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, high-quality
alternative to the Chinese-made scopes prevalent
today.
One problem that might be encountered when
purchasing one of these scopes is that the interocular-
distance adjustment mechanism of the BH2-BI30
binocular viewing head (the BH2-BI30 utilizes a Jentsch
design compensated to maintain a fixed optical tube
length for all settings of interocular distance) may be
stiff or even totally seized, due to the decades-old
grease in the ocular slides and in the tube-length
compensation mechanism.
Scope of this Document
This document describes the complete teardown,
cleaning/lubrication, and reassembly of the BH2-BI30
binocular viewing head (see Figure 1). This Jentsch style
viewing head was an available option for all stands in
the Olympus BH-2 line. The contents of this document
should allow a hobbyist with reasonable mechanical
abilities to perform a complete teardown and
lubrication of the BH2-BI30 binocular viewing head.
This document does not cover the optical alignment of
the viewing head, since alignment to factory
specifications requires specific Olympus tooling which is
no longer available.
Figure 1 –The Jentsch style BH2-BI30 viewing head
Before Attempting Your Own Service
The service procedures described in this document may
adversely impact the alignment of the various optical
components (i.e., prisms) within the BH2-BI30 binocular
viewing head. Specifically, the alignment of the
BH2-BI30 optical path may be impacted to the extent
that the viewing head may no longer pass the original
Olympus factory specifications. However, these
procedures do not typically impact real-world
functioning of the viewing head (if the optical
performance of the viewing head is acceptable to the
microscope operator before the service is performed, it
will almost certainly still be acceptable following this
procedure). Another consideration before deciding
whether or not to perform this repair yourself is that
many (if not most) BH2-BI30 binocular viewing heads
have been field-repaired at some point in their service
lives, and the original factory alignment for these
previously serviced units is likely already compromised.
Common Problems with the BH2-BI30 Head
A few of the more common problems with the BH2-BI30
binocular viewing head are discussed below.
Interocular-Distance Slide is Stiff or Seized
A very common issue with the BH2-BI30 binocular
viewing head is a stiff (or completely seized)
interocular-distance adjustment mechanism. This
problem can be caused by dry or thickened grease in
the greased-dovetail slides for the ocular tubes, or by
dry or thickened grease in the length-compensating
ocular inner tubes. Most often a stubborn interocular-
distance mechanism can be attributed to a combination
of both of these factors, which can be corrected by
performing the cleaning and lubrication procedure
described in this document.
Focus Ring on Left-Hand Ocular Tube is Stiff or Seized
A less common issue with the BH2-BI30 binocular
viewing head is a stiff (or completely seized) helical
focus ring on the left-hand ocular tube. This issue is
typically caused by dry or thickened grease in the
helicoid threads in the focus mechanism, and can be
corrected by following the cleaning and lubrication
procedure described in this document.
Internal Optics are Dirty
Dust, debris, or smudges (fingerprints, etc.) on the
various optical prisms within the BH2-BI30 binocular
viewing head can cause poor contrast or visible artifacts
in the observable field of view. These conditions can
usually be corrected by following the specific
procedures in this document pertaining to the cleaning

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 8 of 34
of the various optical components. Etching or fungus
growth on the optics usually must be corrected by
replacing the affected prism or prisms, which is outside
the scope of this document.
Optical Alignment is Poor
Poor optical performance (e.g., poor centering or
collimation) can result from misaligned prisms in the
BH2-BI30 binocular head. The repair for this is also
outside the scope of this document
Left-Hand and Right-Hand Side Designations
Throughout this document, references are frequently
made to the left-hand and right-hand sides of the
BH2-BI30 binocular viewing head. Unless stated
otherwise, these designations are from the perspective
of the equipment operator. Note that some of the
photos in this document show views from behind the
equipment, or views with the equipment oriented
upside down, and because of this, features referenced
in the text as present on a specific side may appear on
the opposite sides in these photos.
Tools Needed
The following tools will be needed to complete the
teardown, cleaning/lubrication, and reassembly of the
BH2-BI30 binocular viewing head:
Allen wrench or driver: 1.3mm (item 1 of Appendix 1)
Electric heat gun: (item 2 of Appendix 1)
Screwdriver set, JIS (item 3 of Appendix 1)
Screwdrivers, slotted, various sizes
Tweezers (item 4 of Appendix 1)
Electric Heat Gun
An electric heat gun is an absolute necessity for
servicing BH-2 microscopes. Heat is ideal for loosening
old grease to free stuck or stubborn mechanisms, and
for softening the glues and thread-locking adhesives
used throughout these microscopes. Do not try to
service your BH-2 stand without a suitable heat gun
1
.
A Few Words about JIS Screws
Screws with JIS heads are frequently found in much of
the 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
1
Stripped fasteners and foul language will be the inevitable result if you
ignore this warning.
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 2).
Figure 2 –Head of a typical JIS screw
Disassembling the BH2-BI30 Viewing Head
The BH2-BI30 binocular viewing head must be fully
disassembled in order to perform the maintenance
described in this document. One of the first steps in
disassembling the BH2-BI30 is to remove the two plastic
finger grips on the front of the viewing head (over the
ocular tubes), per the procedures described later in this
document. This is necessary so that the screws that
secure the B2-BI frame assembly into the B2-BIC main
housing assembly can be removed. The plastic finger
grips are held onto their respective ocular slides via a
small screw in the front of each one and two screws in
the back of each one. To remove the screws in the
back, the interocular-distance slide mechanism must be
adjusted sufficiently wide to allow access to the heads
of these screws. If for any reason the interocular-
distance mechanism is seized in place and the ocular
tubes cannot be spread sufficiently wide to access these
screws, further disassembly will not be possible and no
further service can be performed. Accordingly, it is
therefore imperative that the slide mechanism be
moved, by hook or by crook, if this is the case
2
.
The first thing to do to try to coax a stuck slide to move
is the application of heat, to loosen the grease in the
mechanism. Use a heat gun to apply gentle heat to the
top, bottom, and sides of the head (just behind the
plastic finger grips), and to the two ocular tubes, such
that the grease in the internal mechanism is gradually
warmed. Do not apply heat directly to the plastic finger
2
You may get lucky and not have to move the interocular slides, if the head is
seized at a wide enough setting that the four screws can be removed.

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 9 of 34
grips, and do not apply too much heat, otherwise the
plastic finger grips may melt and deform. If heat fails to
release the stuck mechanism, apply a few drops of
penetrating oil to the ends of the dovetail slide
components (as visible on both sides of the head),
getting the oil into every nook and cranny that is
accessible, and allow sufficient time for the oil to work
its way into the seized slide mechanism as much as
possible. Repeat this a few times. Next, remove the
helical focus ring from the left ocular tube and the black
trim ring from the right ocular tube, as described later
in this document, and use a cotton swab lightly
moistened with a suitable solvent (e.g., acetone) to
clean as much of the old lubrication from the polished
inside surfaces of the two ocular tubes as possible. Do
not use too much solvent here, or it may drip down
onto the prisms and leave an oily residue that is very
difficult to remove. After the old lubrication has been
cleaned from the ocular tubes as well as possible,
sparingly apply light machine oil to a cotton swab, and
use this to lubricate the polished inner surfaces of the
two ocular tubes. Do not use too much oil here, or it
may drip down onto the prisms. Repeat the heating
procedure described above and attempt once more to
move the ocular slides. If the above steps fail, use a
Panavise® (or similar work vise) and improvise some
method to squeeze the ends of the ocular slides (after
warming per above) to break loose the polymerized
grease and allow the slides to once again move
3
. Once
the polymerized grease has been broken free in this
manner, the ocular tubes should then be able to be
spread, so long as the grease in the slide mechanism is
kept sufficiently warm during the attempt.
Supplies Needed
The following supplies will be needed to complete the
teardown, cleaning/lubrication, and reassembly of the
BH2-BI30 binocular viewing head:
Cleaning solvent (see Recommended Solvents below)
Cotton swabs
Lens wipes, pre-moistened (item 7 of Appendix 1)
Lubricants (see Recommended Lubricants below)
Recommended Solvents
Some type of cleaning solvent will be needed to remove
the old grease from the various components of the
BH2-BI30 binocular viewing head. Solvents that can be
used are acetone (commonly sold as fingernail polish
remover), diethyl ether, heptane, hexane, mineral
spirits, turpentine, and xylene. Of the solvents listed,
3
Attempt this ONLY if the ocular tubes are not already at their minimum
spacing, otherwise damage to the binocular viewing head may result.
acetone fingernail polish remover is available in most
grocery or department stores. Look for a fingernail
polish remover that is labeled as 100% acetone.
Safety Considerations with Solvents
Regardless of whichever 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
MSDS sheet before using any unfamiliar solvents. Many
of the solvents listed above are flammable, and their
vapors may represent an explosion hazard if
mishandled. Whichever solvents are chosen, be sure to
follow all manufacturer’s instructions and safety
precautions.
Solvent Compatibility with Parts and Finishes
Many solvents will damage the finish of painted
surfaces (isopropyl alcohol or 409 cleaner may be safely
used to clean most painted surfaces) or will dissolve or
damage plastic parts. Do not allow untested solvents to
contact any plastic parts or any painted surfaces.
Before using a solvent to clean plastic parts or painted
surfaces, test a small amount of the solvent in an
inconspicuous area (such as inside a plastic knob) to
ensure compatibility with the plastic parts or painted
surfaces. Never use xylene to clean nylon parts, as
xylene dissolves nylon. Isopropyl alcohol and
trichloroethylene will cause swelling of nylon due to
solvent absorption. The list of solvents generally
considered safe for nylon includes acetone, diethyl
ether, heptane, mineral spirits, naphthalene, and
turpentine.
Recommended Lubricants
Molykote® 44 Light (item 5 of Appendix 1) is the
recommended lubricant for the interocular slides and
for the ocular tube-length-compensation tubes in the
BH2-BI30 binocular viewing head. HELIMAX-XPTM
helicoid grease (item 6 of Appendix 1) is the
recommended lubricant for the helical focus
mechanism.
Label Parts for Identification and Reassembly
There are many small parts that make up the BH2-BI30
binocular viewing head. It is critical that these be
bagged and tagged as they are removed, to prevent
them from getting lost and to facilitate their proper
identification during reassembly.
Servicing the BH2-BI30 Binocular Viewing Head
Proceed with the repair of the BH2-BI30 binocular
viewing head per the following procedure.

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 10 of 34
Remove the Helical Focus Ring (Left)
Use a 1.3mm (or .050”) Allen wrench or driver to loosen
the three M2.6x4 set screws securing the helical focus
ring onto the left-hand ocular tube (see Figure 3).
Figure 3 –Loosen set screws securing helical focus ring (left)
Remove the (now loose) helical focus ring from the left-
hand ocular tube (see Figure 4).
Figure 4 –Remove helical focus ring from ocular tube (left)
Remove the Plastic Finger Grip (Left)
Adjust the interocular-distance slide such that the two
M2.6x5 JIS screws securing the left-hand finger grip to
the left-hand ocular slide are accessible from the rear of
the unit (see Figure 5).
Figure 5 –Screws securing finger grip to the slide (left)
Use a suitable JIS screwdriver to remove the two
M2.6x5 JIS screws securing the left-hand finger grip
onto the left-hand ocular slide (see Figure 6).
Figure 6 –Remove screws securing finger grip (left)
Use a suitable JIS screwdriver to remove the M2x10 JIS
screw from the front of the left-hand finger grip (see
Figure 7).
Figure 7 –Remove front screw from finger grip (left)
Remove the (now loose) left-hand finger grip from the
left-hand ocular tube (see Figure 8).
Figure 8 –Remove finger grip from ocular tube (left)

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 11 of 34
Remove the Plastic Finger Grip (Right)
Adjust the interocular-distance slide such that the two
M2.6x5 JIS screws securing the right-hand finger grip
are accessible from the rear of the right-hand ocular
slide (see Figure 9).
Figure 9 –Screws securing finger grip to slide (right)
Use a suitable JIS screwdriver to remove the two
M2.6x5 JIS screws securing the right-hand finger grip
onto the right-hand ocular slide (see Figure 10).
Figure 10 –Remove screws securing finger grip (right)
Use a suitable JIS screwdriver to remove the M2x10 JIS
screw from the front of the right-hand finger grip (see
Figure 11).
Figure 11 –Remove front screw from finger grip (right)
Remove the (now loose) right-hand finger grip from the
right-hand ocular tube (see Figure 12).
Figure 12 –Remove finger grip from ocular tube (right)
Remove the Graduated Center Cover
Use a suitable JIS screwdriver to remove the four M2x4
JIS screws (two on top, two on bottom) securing the
graduated center cover to the front frame of the
viewing head (see Figure 13 and Figure 14).
Figure 13 –Remove screws securing center cover (top)
Figure 14 –Remove screws securing center cover (bottom)
Remove the (now loose) graduated center cover from
the front frame (see Figure 15).

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 12 of 34
Figure 15 –Remove the center cover from the frame
Remove the Frame Assembly from the Main Housing
Adjust the interocular-distance slide such that the four
M3x6 JIS screws securing the B2-BI frame assembly to
the B2-BIC main housing assembly are accessible (see
Figure 16).
Figure 16 –Screws securing front frame to the main housing
Use a suitable JIS screwdriver to remove the four M3x6
JIS screws securing the B2-BI frame assembly to the
B2-BIC main housing assembly (see Figure 17).
Figure 17 –Remove screws securing front frame to housing
Carefully remove the B2-BI frame assembly from the
B2-BIC main housing assembly (see Figure 18), being
careful not to damage or smudge the prisms in the
process.
Figure 18 –Remove frame assembly from main housing
Remove Mounting Disk Assembly from Main Housing
For routine cleaning and lubrication of the BH2-BI30 binocular
viewing head, there is no reason to remove the mounting disk from
the main housing, but the removal and reinstallation procedure is
included below for the sake of completeness of this document.
INCLUDED FOR REFERENCE
Apply adhesive tape to the outer surface of the main
housing to mark the position in which mounting disk
assembly is currently installed. This will allow the
mounting disk assembly to be reinstalled into the same
relative position later, thereby minimizing any effect of
P1/P2 prism misalignment on the optical performance
of the reassembled viewing head (see Figure 19).
Figure 19 –Apply tape to mark placement of mounting disk
Use a suitable JIS screwdriver to remove the three
M3x8 JIS screws securing the mounting disk assembly
onto the main housing (see Figure 20).
Figure 20 –Remove screws securing mounting disk assembly

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 13 of 34
Remove the (now loose) mounting disk assembly from
the main housing (see Figure 21 and Figure 22).
Figure 21 –Remove the mounting disk assembly
Figure 22 –The mounting disk assembly
Reinstall Mounting Disk Assembly onto Main Housing
INCLUDED FOR REFERENCE
Place the mounting disk assembly into position on the
bottom of the main housing and align the three holes in
the circular dovetail disk with the tapped holes in the
main housing (see Figure 23).
Figure 23 –Place the mounting disk assembly into position
Use a suitable JIS screwdriver to loosely reinstall three
M3x8 JIS screws to hold the mounting disk assembly
onto the main housing (see Figure 24). Carefully align
the edges of the circular dovetail disk with the witness
tapes applied earlier and tighten the three M3x8 JIS
screws to secure the mounting disk assembly in its
original position (see Figure 24).
Figure 24 –Secure the mounting disk assembly in position
Remove the Tension Springs for the Follower Keys
The two tension springs for the tube-length-correction
follower keys are shown in Figure 25. Note that
(neglecting the coiled portions) one spring is straight
and the other is bent. Although the disassembly photos
in this document show the straight spring removed
from the right-hand follower key and the bent spring
removed from the left-hand follower key, the springs
may be found installed on either side.
Figure 25 –The tensions springs for the follower keys
Grasp the end of the straight tension spring and lift the
end above the slotted retaining screw to relieve the
pre-load on the straight spring (see Figure 26).
Figure 26 –Relieve the pre-load on the straight spring

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 14 of 34
Use a suitable slotted screwdriver to remove the slotted
retaining screw securing the straight tension spring to
the spring-mounting bracket on the P3/P4 prism mount
(see Figure 27) and remove the straight tension spring
(see Figure 28).
Figure 27 –Remove the screw securing the straight spring
Figure 28 –Remove the straight spring
Use a suitable slotted screwdriver to remove the slotted
retaining screw securing the bent tension spring to the
spring-mounting bracket on the P3/P4 prism mount
(see Figure 29) and remove the bent tension spring (see
Figure 30).
Figure 29 –Remove the screw securing the bent spring
Figure 30 –Remove the bent spring
Remove the Follower Keys
Use a suitable slotted screwdriver to remove the right-
hand (see Figure 31) and left-hand (see Figure 32)
follower keys from the slots in the top of the frame.
Figure 31 –Remove the follower key (right)
Figure 32 –Remove the follower key (left)
Clean Inner Tubes and Regrease the Helical Focus Ring
Grasp the ring of the black helical tube and withdraw
the helical tube and polished inner tube together from
the left-hand ocular tube (see Figure 33).

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 15 of 34
Figure 33 –Remove helical/polished inner tubes (left)
Use a suitable solvent (e.g., acetone) to thoroughly
clean the old grease from the outer surface of the
polished inner tube (see Figure 34).
Figure 34 –Remove grease from inner tube (left)
Unscrew and remove the black helical tube from the
polished inner tube (see Figure 35).
Figure 35 –Unscrew helical tube from the inner tube (left)
Use a suitable solvent (e.g., acetone) to thoroughly
remove the old grease from the outer helicoid threads
of the black helical tube (see Figure 36).
Figure 36 –Clean old grease from the outer helicoid threads
Use a suitable solvent (e.g., acetone) to thoroughly
remove the old grease from the inner helicoid threads
of the polished inner tube (see Figure 37).
Figure 37 –Clean grease from threads of inner tube (left)
Apply a very light coating of fresh helicoid grease (item
6 of Appendix 1) to the outer helicoid threads of the
black helical tube (see Figure 38) and to the inner
helicoid threads of the polished inner tube (see Figure
39).
Figure 38 –Apply fresh grease to the outer helicoid threads

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 16 of 34
Figure 39 –Apply fresh grease to inner helicoid threads (left)
Carefully reinstall the black helical tube into the
polished inner tube
4
(see Figure 40). Screw the helical
tube fully into the polished inner tube and remove any
visible grease squeeze-out from both ends of the
mechanism.
Figure 40 –Thread the helical tube into the inner tube (left)
Use a suitable solvent (e.g., acetone) to thoroughly
clean the old grease from the polished inner surface of
the left-hand ocular tube (see Figure 41).
Figure 41 –Remove grease from the ocular tube (left)
4
Perfect alignment of the helicoid tubes is necessary for the threads to go
into engagement. Keep trying and do not force it. This may take a while.
Temporarily reinsert the ungreased polished inner tube,
with the black helical tube, into the left-hand ocular
tube (see Figure 42), making sure the tab for the
follower key is oriented towards the top and that this
tab inserts into the notched opening in the ocular tube.
Figure 42 –Reinstall the inner / helical tubes (left)
Using tweezers in the small notch in the trim ring on the
right-hand ocular tube, grasp the trim ring and carefully
remove it from the ocular tube (see Figure 43).
Figure 43 –Remove black trim ring from ocular tube (right)
Grasp the fixed sleeve attached to the polished inner
tube and withdraw the fixed tube and polished inner
tube together from the right-hand ocular tube (see
Figure 44).
Figure 44 –Remove the fixed sleeve/inner tubes (right)

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 17 of 34
Use a suitable solvent (e.g., acetone) to thoroughly
clean the old grease from the outer surface of the
polished inner tube (see Figure 45).
Figure 45 –Remove grease from the inner tube (right)
Use a suitable solvent (e.g., acetone) to thoroughly
clean the old grease from the polished inner surface of
the right-hand ocular tube (see Figure 46).
Figure 46 –Remove grease from the ocular tube (right)
Temporarily reinsert the ungreased polished inner tube
(with attached fixed sleeve) into the right-hand ocular
tube (see Figure 42), making sure the tab for the
follower key is oriented towards the top and that this
tab inserts into the notched hole inside the ocular tube.
Figure 47 –Reinstall the fixed sleeve / inner tube (right)
Remove the Ocular Slide Assembly (Left)
Use a suitable JIS screwdriver to remove the two
M2.6x5 JIS screws securing the left-hand dovetail block
onto the left-hand side of the front frame (see Figure
48).
Figure 48 –Remove screws securing dovetail block (left)
Remove the (now loose) left-hand dovetail block from
the left-hand side of the front frame (see Figure 49).
Figure 49 –Remove dovetail block from the frame (left)
Lift the left-hand ocular slide assembly to disengage its
lower bevel from the bottom dovetail in the front
frame, and carefully remove the left-hand ocular slide
assembly from the frame by pulling it out from the front
of the frame (see Figure 50), making sure that the P6
prism is neither scratched nor smudged in the process.
Figure 50 –Remove the ocular slide assembly (left)

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 18 of 34
The components of the left-hand ocular slide assembly
are shown in Figure 51.
Figure 51 –The ocular slide assembly (left)
Remove the Ocular Slide Assembly (Right)
Use a suitable JIS screwdriver to remove the two
M2.6x5 JIS screws securing the right-hand dovetail
block onto the front frame (see Figure 52).
Figure 52 –Remove screws securing dovetail block (right)
Remove the (now loose) right-hand dovetail block from
the front frame (see Figure 53).
Figure 53 –Remove dovetail block from frame (right)
Lift the right-hand ocular slide assembly to disengage its
lower bevel from the bottom dovetail in the front
frame, and carefully remove the right-hand ocular slide
assembly from the frame by pulling it out the front of
the frame (see Figure 54), making sure that the P5
prism is neither scratched nor smudged in the process.
Figure 54 –Remove the ocular slide assembly (right)
The components of the right-hand ocular slide assembly
are shown in Figure 55.
Figure 55 –The ocular slide assembly (right)
Remove the Brass Pivot Lever
Use a suitable slotted screwdriver to remove the slotted
pivot-shaft screw holding the brass pivot lever in place
(see Figure 56) and remove the brass pivot lever from
the center support of the front frame (see Figure 57).
Figure 56 –Remove screw holding brass pivot lever in place

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 19 of 34
Figure 57 –Remove brass pivot lever from the frame
Clean the Various Mechanical Parts
Use a suitable solvent (e.g., acetone) to remove the old
grease from the brass pivot lever (see Figure 58).
Figure 58 –Clean old grease from the brass pivot lever
Use a suitable solvent (e.g., acetone) to remove the old
grease from the pivot-lever bearing surface on the
center support of the front frame (see Figure 59).
Figure 59 –Clean grease from pivot-lever bearing surface
Use a suitable solvent (e.g., acetone) to remove the old
grease from the dovetail bevels for the left-hand and
right-hand ocular slides in the bottom channel of the
front frame (see Figure 60).
Figure 60 –Clean grease from the lower dovetail bevels
Use a suitable solvent (e.g., acetone) to remove the old
grease from the flat upper sliding surfaces for the left-
hand and right-hand ocular slides, and from the four
index pins protruding from the frame (see Figure 61).
Figure 61 –Clean old grease from upper sliding surfaces
Use a suitable solvent (e.g., acetone) to remove the old
grease from the beveled dovetail surfaces on the right-
hand (see Figure 62) and left-hand (see Figure 63)
ocular slides.
Figure 62 –Clean old grease from bevels of slide (right)

Complete Teardown, Cleaning, and Reassembly of the Olympus BH2-BI30 Binocular Viewing Head (Rev. 1) Page 20 of 34
Figure 63 –Clean old grease from bevels of slide (left)
Use a suitable solvent (e.g., acetone) to remove the old
grease from the rear sliding surfaces of the right-hand
(see Figure 64) and left-hand (see Figure 65) ocular
slides.
Figure 64 –Clean old grease from back of slide (right)
Figure 65 –Clean old grease from back of slide (left)
Use a suitable solvent (e.g., acetone) to remove the old
grease from the two dovetail blocks (see Figure 66).
Figure 66 –Clean old grease from both dovetail blocks
Remove the P3/P4 Prism Mount
For routine cleaning and lubrication of the BH2-BI30 binocular
viewing head, there is no reason to remove the P3/P4 prism mount
from the front frame, but the removal and reinstallation procedure
is included below for the sake of completeness of this document.
INCLUDED FOR REFERENCE
Use a suitable slotted screwdriver to remove the two
M3x5 slotted screws securing the P3/P4 prism mount
onto the back side of the center support of the front
frame (see Figure 67).
Figure 67 –Remove screws securing the P3/P4 prism mount
Carefully remove the P3/P4 prism mount, with P3 and
P4 prisms attached (see Figure 68 and Figure 69).
Figure 68 –Remove P3/P4 prism mount with prisms